NRLF 


B 


UNITED  STATES  PATENT  OFFICE 


THE  CLASSIFICATION  OF  PATENTS 


WASHINGTON 

GOVERNMENT  PRINTING  OFFIC1 
1915 


UNITED  STATES  PATENT  OFFICE 


THE  CLASSIFICATION  OF  PATENTS 


WASHINGTON 

GOVERNMENT  PRINTING  OFFICE 
1915 


CAT.  FOR 
LOAN  STACK 
(DOC.  COLL) 


°i\S 


PREFATORY  NOTE. 


Parts  A  and  B  of  the  following  pages  are  designed  to  acquaint  all 
persons  using  the  Patent  Office  classification  with  the  principles  upon 
which  the  reclassification  is  proceeding. 

Part  C  consists  of  a  few  tentative  rules  advanced  with  the  notion 
of  fixing  classification  practice  within  the  office  in  certain  doubtful 
cases. 

Part  D  is  intended  to  inform  examiners  reclassifying  within  exam- 
ining divisions  respecting  the  initial  procedure  in  reforming  a  class. 

ni 


195 


CONTENTS. 


Page. 

A.  Introduction 1 

Past  classifications  of  the  U.  S.  Patent  Office 1 

Beginning  of  revision 2 

Precedents  and  authorities 3 

Definition  of  scientific  classification 4 

B.  Principles  of  the  new  classification  of  the  Patent  Office 4 

Elements  of  a  Patent  Office  classification 4 

Basis  of  classification 5 

Art  as  a  basis 5 

Function  or  effect  as  a  basis 7 

Structure  as  a  basis 8 

Division  and  arrangement 9 

Infinitude  of  possible  combinations 10 

Division  and  arrangement  in  the  natural  sciences 10 

Difficulty  of  entitling  a  subclass  corresponding  to  every  combi- 
nation   11 

Expedients  to  reduce  the  number  of  subdivisions 12 

Superiority  and  inferiority 15 

Definite  positional  relationship  of  subdivisions 16 

Indented  schedules 17 

Bifurcate  division 19 

Utility  of  arrangement  according  to  resemblances 19 

Definition 20 

Cross-references  and  search-notes 21 

Diagnosis  to  determine  classification 22 

Claimed  or  unclaimed  disclosure 22 

Diagnosis  of  pending  applications 23 

Difficulties  due  to  varying  ideas  of  claims 25 

C.  Rules  of  classification 26 

Basis  of  classification 26 

1 .  "  Art "  as  the  basis 26 

2.  Operative  or  manipulative  arts 26 

3.  Structures 26 

4.  Composition  of  matter  and  formed  stock 26 

Division  and  arrangement 27 

5.  Exhaustive  division;  miscellaneous  subclass 27 

6.  Subclasses  not  to  overlap 27 

7.  Subclasses  of  any  group  to  be  formed  on  one  basis 27 

8.  Apparent  exception  to  rules  6  and  7 27 

9.  Relative  position  of  subclasses 27 

10.  Indention  of  subclasses 29 

11.  Different  kinds  of  titles  for  subclasses 29 

12.  Arrangement  to  limit  search  and  cross  references 30 

Definition 30 

13.  Tentative  definition 30 

14.  How  to  define 30 

15.  Explanatory  notes  may  sometimes  displace  definition 31 

v 


VI  CONTENTS. 

C.  Rules  of  classification — Continued.  Page. 

Cross-references  and  search-notes 31 

16.  Impossibility  of  cross-referencing  all  disclosures 31 

17.  Occasion  and  direction  of  cross-referencing 31 

18.  Occasion  and  scope  of  search-notes 32 

Diagnosis  to  determine  classification 32 

19.  Patents  diagnosed  by  claimed  disclosure 32 

20.  Patents  diagnosed  by  most  intensive  claim 33 

21.  Exception  to  rule  19,  claim  for  a  part  of  a  disclosed  combination.  33 

22.  Exception  to  rule  19,  claims  for  a  part  of  a  disclosed  combination.  33 

23.  Exception  to  rule  19,  generic  combination  old  as  matter  of  com- 

mon knowledge 34 

24.  Exception  to  rule  19,  article  of  manufacture  defined  only  by 

material 34 

25.  Exception  to  rule  19,  utilizing  a  composition 34 

26.  Exception  to  rule  19,  utilizing  a  machine 34 

27.  Patents  having  claims  for  several  different  inventions 35 

28.  General  rule  of  superiority  between  statutory  kinds  of  invention.  35 

29.  Exception  to  rule  28 35 

30.  Process  and  apparatus 36 

31.  Article  of  manufacture  and  instrument  for  making  a  part  of  it  or 

performing  any  minor  act  relative  thereto 36 

32.  Process  and  product  where  search  for  the  process  would  have  to 

be  made  among  machines 36 

33.  Process  and  product  where  search  for  the  process  would  have  to 

be  made  among  products 36 

34.  Process  of  making  a  composition  and  the  composition  where 

the  process  is  peculiarly  adapted  to  make  the  composition 37 

35.  Article  of  manufacture  or  composition  and  process  for  making 

one  of  the  parts  of  the  article  or  ingredients  of  the  composition .  37 

D.  Procedure  in  reclassifying  within  examining  divisions 37 

1.  General  attitude 37 

Procedure  involving  only  cursory  scrutiny  of  familiar  patents — 

2.  Consider  wholes  in  forming  tentative  subdivisions  of  subclasses. .  38 

3.  Write  tentative  definitions  of  subdivisions 38 

4.  Consider  the  significance  of  analogies  found  to  traverse  parts  of 

two  or  more  existing  subclasses 38 

5.  Arrange  groups  on  parallel  or  accordant  lines  where  practicable..  38 

6.  Watch  for  subcombinations  deserving  separate  recognition 38 

7.  Consider  whether  the  groups  collectively  will  constitute  a  proper 

class  and  their  best  correlation 38 

Procedure  involving  rigorous  analysis — 

8.  Diagnose  each  patent  for  original  classification 39 

9.  Group  and  consider  the  disposition  of  patents  deemed  foreign  to 

the  class 39 

10-15.  Consider  and  indicate  cross-referencing  within  and  to  and 

from  the  class 39;  40 

Note..                                                                                          40 


THE  CLASSIFICATION  OF  PATENTS. 

(A)  INTRODUCTION. 


Classification  lies  at  the  foundation  of  the  mental  processes.  Without  the  power 
of  perceiving,  recognizing  resemblances,  distinguishing  differences  in  things,  phe- 
nomena and  notions,  grouping  them  mentally  according  to  those  resemblances  and 
differences,  judgment  is  impossible,  nor  could  reason  be  exercised  in  proceeding 
from  the  known  to  the  unknown. 

**•**•*•** 

The  facilitation  and  abbreviation  of  mental  labor  is  at  the  bottom  of  all  mental 
progress.  The  reasoning  faculties  of  Newton  were  not  different  in  qualitative  char- 
acter from  those  of  a  ploughman;  the  difference  lay  in  the  extent  to  which  they  were 
exerted  and  the  number  of  facts  which  could  be  treated.  Every  thinking  being 
generalizes  more  or  less,  but  it  is  the  depth  and  extent  of  his  generalizations  which 
distinguish  the  philosopher.  Now  it  is  the  exertion  of  the  classifying  and  generalizing 
powers  which  thus  enables  the  intellect  of  man  to  cope  in  some  degree  with  the 
infinite  number  and  variety  of  natural  phenomena  and  objects.  (Jevons,  Principles 
of  Science.) 

PAST  CLASSIFICATIONS  OF  UNITED  STATES  PATENT  OFFICE. 

As  under  the  patent  laws  the  people  of  the  United  States  assume 
all  the  risks  in  granting  a  patent  for  any  means  of  the  "  useful  arts/' 
a  classification  that  will  facilitate  a  judgment  respecting  the  patent- 
ability of  any  means  presented  to  the  Patent  Office  is  of  peculiar 
moment.  The  enormous  extent,  diversity,  and  refinement  of  the 
useful  arts  preclude  the  formation  of  a  judgment  on  novelty  within  a 
reasonable  tune,  unless  the  necessary  comparisons  with  known  proc- 
esses and  instruments  have  been  previously  made  along  the  lines 
that  searches  must  follow  and  the  results  of  such  comparisons  made 
available  in  a  classification.  The  vast  majority  of  available  dis- 
closures of  the  arts  occur  in  patents.  Hence  the  Patent  Office 
classification  must  be  adjusted  in  the  main  to  the  analysis,  diagnosis, 
and  orderly  arrangement  of  the  disclosures  of  patents. 

For  more  than  80  years  United  States  patents  have  been  classified. 
The  first  published  classification,  promulgated  in  1830,  comprised 
6, 170  patents,  divided  into  1 6  classes.  The  change  from  a  registration 
to  an  examination  system  in  1836  instigated  a  new  classification  in  22 
classes,  including  9,800  patents.  The  next  came  in  1868  with  36 
classes,  including  about  75,000  patents.  On  March  1, 1872,  a  revised 
classification  was  adopted,  comprising  145  classes,  including  131,000 

l 


2  CLASSIFICATION   OF  PATENTS. 

patents.  This  classification  is  said  to  have  been  planned  by  Dr. 
Edward  H.  Knight.  The  placing  of  the  patents  in  accordance  with 
the  schedule  of  classes  is  said  to  have  been  done  by  the  several 
examiners.  The  class  arrangement  was  purely  alphabetical  by  class 
titles,  and  the  number  designations  followed  the  alphabetical  order. 
The  names  of  things  to  be  found  in  the  several  classes  were  arranged 
alphabetically  under  each  class  title.  No  attempt  was  made  to 
bring  the  titles  of  allied  materials  into  juxtaposition  or  to  effect  other 
definite  arrangement  with  reference  to  subject  matter  in  the  printed 
schedules.  A  consolidated  name  index  supplemented  the  list  of 
names  by  classes. 

This  classification  of  1872  is  hi  part  the  classification  that  now 
exists,  many  of  the  same  class  numbers  and  titles  being  still  in  use. 
Examiners  were  apparently  permitted  to  make  changes  in  classifica- 
tion to  suit  their  convenience  without  notice  until  1877.  In  that 
year  a  revision  of  the  published  schedule  was  made  by  a  committee, 
resulting  hi  the  addition  of  13  new  classes,  and  examiners  were 
ordered  to  transfer  patents  in  accordance  with  the  new  titles.  The 
first  classification  published  with  distinct  subclasses  appeared  in  1880. 
From  that  time  until  1898  the  classification  grew  by  addition  and 
subdivision  of  classes  to  suit  the  ends  of  individual  examiners  or  in 
response  to  supposed  exigencies  of  the  work  where  one  division  was 
thought  to  be  overloaded  and  another  underloaded,  and  the  alpha- 
betical arrangement  of  subclasses  under  each  class  has  succeeded  the 
alphabetical  list  of  names.  The  arbitrary  correspondence  originally 
established  between  the  alphabetical  order  of  class  titles  and  the 
numerical  order  was  destroyed  as  soon  as  expansion  of  the  classi- 
fication began. 

However  suitable  to  the  then-existing  material  of  the  useful  arts 
the  classification  of  1872  may  have  been,  it  failed  as  fail  all  inductive 
processes  wherein  the  generalizations  are  not  broad  and  deep.  (Isaac 
Newton's  intellect  could  detect  the  resemblance  between  the  falling 
fruit  and  the  motions  of  the  planets.)  The  classification  of  1872  was 
not  exhaustive;  it  failed  to  recognize  to  the  fullest  extent  what 
Bishop  Wilkins  saw  nearly  300  years  ago,  to  wit,  that  there  are  "  arts 
of  arts;"  and  it  failed  to  provide  for  future  invention  of  new  species 
in  the  same  art,  and  to  recognize  that  new  arts  could  be  formed  from 
combinations  of  the  old. 

BEGINNING  OF  REVISION. 

The  Classification  Division  was  created  in  the  hope  that  guiding 
principles  of  classification  could  be  developed  and  applied  for  the 
purpose  of  amending  or  revising  the  classification  whereby  patents 
could  be  placed  with  greater  assurance,  and  whereby  the  searcher 


CLASSIFICATION   OF   PATENTS.  3 

with  these  guiding  principles  in  mind  might  find  the  nearest  refer- 
ences. It  was  confronted  with  the  problem  of  revising  while  at  the 
same  time  keeping  accurate  record  of  all  changes,  correcting  all 
indexes  of  patents,  and  using  copies  in  constant  demand  for  search 
at  the  same  tune,  necessitating  much  clerical  work,  and  constant 
interruption — of  correcting  rather  than  plaiining  anew;  of  mending 
a  machine  while  constantly  increasing  duty  was  required  of  it. 

Ideas  on  the  subject  of  revision  were  called  for  by  the  Commis- 
sioner of  Patents,  and  all  in  the  Patent  Office  had  an  opportunity 
to  set  forth  their  notions.  The  views  of  one  met  with  approval  and  in 
accordance  with  those  views  a  "Plan  of  Classification"  was  prepared 
and  promulgated  in  1900.  What  other  plans  may  have  been  sub- 
mitted is  not  now  generally  known.  But  in  substantial  accordance 
with  that  published  plan,  the  process  of  revision  has  proceeded  for 
more  than  14  years  until  approximately  50  per  cent  of  the  patents 
(including  incomplete  work)  have  been  placed  in  revised  classes. 

PRECEDENTS  AND  AUTHORITIES. 

No  effective  precedents  have  been  found  in  any  prior  classifications 
of  the  arts.  The  classifications  of  the  principal  foreign  patent  of- 
fices have  not  been  materially  different  in  principle  from  the  United 
States  Patent  Office  classifications  of  the  past. 

The  divisions  found  suitable  for  book  classification  for  library  use, 
have  not  been  deemed  adequate  to  the  exactness  and  refinement 
essential  to  a  patent  office  classification  of  the  useful  arts.  The  sys- 
tems of  class  and  subclass  sign  or  number  designations  of  the  modern 
library  classifications,  with  their  mnemonic  significance,  afford  the 
most  important  suggestions  to  be  drawn  from  library  classification. 
None  of  these  systems  of  designation  has  been  adopted,  (1)  because 
of  a  serious  doubt  as  to  the  availability  of  such  designations  by 
reason  of  the  length  or  unwieldiness  to  which  they  would  attain  in 
the  refinements  of  division  necessary  in  a  patent  office  classification, 
and  (2)  because  of  the  enormous  amount  of  labor  necessary  to  make 
the  change  from  present  practice. 

The  best  analogies  are  in  the  known  (but  changing)  classifications 
of  the  natural  sciences,  and  in  them  the  problems  are  so  different 
that  they  can  serve  only  to  illustrate  general  principles.  The  broad 
principles  of  classification  are  well  understood.  The  authorities  are 
the  logicians  from  the  ancient  Aristotle  to  the  modern  Bentham, 
Mill,  and  Jevons.  The  effort  of  the  Classification  Division  has  been 
to  adapt  and  apply  these  well-known  principles  to  the  enormously 
diversified  useful  arts,  particularly  as  disclosed  in  patents  and  appli- 
cations for  patents. 

79163—15 2 


4  CLASSIFICATION    OF   PATENTS. 

DEFINITION  OF  SCIENTIFIC  CLASSIFICATION. 

It  may  be  well  to  insert  here  an  authoritative  definition:  "  A  scien- 
tific classification  is  a  series  of  divisions  so  arranged  as  best  to  facili- 
tate the  complete  and  separate  study  of  the  several  groups  which  are 
the  result  of  the  divisions  as  well  as  of  the  en  tire  subject  under  inves- 
tigation." (Fowler,  Inductive  Logic.) 

Investigation  and  study  of  any  'subject  will  be  facilitated  if  the 
facts  or  materials  pertinent  to  that  subject  be  so  marshaled  and 
arranged  that  those  most  pertinent  to  it  may  appear  to  the  mind  in 
some  form  of  juxtaposition.  It  is  the  purpose  of  the  Patent  Office 
classification  to  divide  and  arrange  the  body  and  multitudinous  units 
of  the  useful  arts  so  that,  having  the  question  of  novelty  of  any  defined 
means  to  answer,  one  may  with  reasonable  assurance  approach  that 
portion  of  the  rank  of  arts  in  which  it  will  be  found  if  it  is  not  new, 
and  in  propinquity  to  which  will  also  be  found  those  means  that  bear 
the  closest  resemblances  to  that  sought  for,  the  resemblances  of  other 
units  growing  less  in  proportion  to  their  distance  therefrom. 

Success  in  the  fundamental  aim  of  facilitating  adequate  search 
should  evidently  at  the  same  time  reduce  proportionately  the  danger 
that  interfering  applications  will  be  overlooked  and  also  effect  a  dis- 
tribution of  labor  favorable  to  the  acquisition  of  special  skill. 

(B)  PRINCIPLES  OF  THE  NEW  CLASSIFICATION  OF  THE  PATENT 

OFFICE. 

THE  ELEMENTS  OF  A  PATENT  OFFICE  CLASSIFICATION. 

A  classification  will  be  useful  in  proportion  (1)  to  the  pertinence  to 
the  subject  under  investigation  of  the  facts  selected  to  be  grouped 
together,  or,  in  other  words,  in  proportion  to  the  appropriateness  of 
the  "basis  of  classification"  to  the  subject  in  hand;  (2)  to  the  con- 
venience, stability,  and  uniformity  of-  the  arrangement  of  the  sub- 
divisions whereby  the  investigator  may  proceed  with  reasonable 
assurance  to  that  portion  of  the  rank  of  groups  within  which  he  will 
find  cognate  material;  (3)  to  the  accuracy  and  perspicuity  of  the 
definitions  of  the  several  divisions  and  subdivisions;  (4)  to  the  com- 
pleteness and  reliability  of  the  cross-referencing  and  cross-notations; 
(5)  to  the  uniformity,  feasibility,  and  certainty  of  the  rules  by  which 
the  accessions  of  patents  disclosing  one  or  several  inventions  may  be 
diagnosed  and  distributed  to  the  appropriate  divisions  of  the  classifi- 
cation in  accordance  with  the  basis  adopted. 

Corresponding  to  the  foregoing  analysis  the  theory  of  Patent  Office 
classification  may  be  treated  in  five  parts:  (1)  The  principles  on 
which  the  arts  shall  be  divided  (basis  of  classification) ;  (2)  subdivi- 
sion and  mechanical  arrangement  of  groups;  (3)  definition;  (4)  cross- 
referencing  and  search-notes;  (5)  the  choice  of  features  by  which  a 
patent  shall  be  assigned  in  the  classification  (diagnosis). 


CLASSIFICATION    OF   PATENTS.  5 

BASIS    OF    CLASSIFICATION. 

The  first  and  most  vital  factor  in  any  system  of  classification  is  the 
basis  of  division,  that  is,  the  kind  of  characteristics  common  to  any 
number  of  objects  selected  to  characterize  groups,  whereby  the  indi- 
viduals of  any  group  will  resemble  each  other  for  the  purpose  in 
view  more  closely  than  any  individual  in  any  group  will  resemble 
any  individual  in  any  other  group. 

" There  is  no  property  of  objects  which  may  not  be  taken,  if  we 
please,  as  the  foundation  for  a  classification  or  mental  grouping  of 
those  objects,  and  in  our  first  attempts  we  are  likely  to  select  for  that 
purpose  properties  which  are  simple,  easily  conceived,  and  percepti- 
ble in  a  first  view  without  any  previous  process  of  thought  — but  these 
classifications  are  seldom  much  adapted  to  the  ends  of  that  classifica- 
tion which  is  the  subject  of  our  present  remarks."  (J.  S.  Mill, 
System  of  Logic.) 

It  is  clear  that  a  number  of  objects  may  be  classified  on  several 
different  bases.  For  example,  a  number  of  books  could  be  divided 
into  groups  (1)  according  to  the  subject  of  their  contents;  (2)  accord- 
ing to  the  language  in  which  the  books  are  written;  (3)  according  to 
the  size  of  page;  (4)  according  to  the  binding  material;  or  (5)  accord- 
ing to  the  color  of  the  binding.  Each  of  these  may  be  useful  classi- 
fications for  some  purpose.  For  the  student  of  literature  none  is  of 
value  except  the  first;  for  the  connoisseur  in  bindings,  only  the  last 
three.  A  classification  of  animals  including  classes  of  land  animals 
and  water  animals  would  hardly  suit  a  student  of  zoology,  as  it  would 
associate  with  the  shad  and  perch  such  differently  organized  creatures 
as  the  porpoise,  whale,  and  seal.  Yet  such  a  classification  might 
prove  very  suitable  for  a  student  of  fisheries. 

Art  as  a  basis.1 — So  in  seeking  a  basis  for  a  patent  office  classifica- 
tion the  purposes  of  the  classification  should  be  the  guide.  Allega- 
tions of  ulterior  uses 2  (such  as  may  be  made  merely  because  the  in- 
ventor thought  of  applying  his  invention  to  those  uses  only,  or  in  an 
effort  to  get  the  application  examined  in  a  certain  division)  and  other 
superficial  bases  should  be  avoided.  That  basis  will  best  suit  the 
purpose  which  effects  such  an  arrangement  as  will  exhibit  in  suitable 
groups  the  "  state  of  the  prior  art,"  by  which  is  here  meant  not  neces- 
sarily all  the  instruments  of  a  trade  or  industry,  or  all  the  articles 
sold  by  a  shopkeeper,  as  a  stationer,  but  those  means  that  achieve 

1  An  "art,"  in  the  sense  of  a  single  unitary  invention,  is  a  synonym  of  process,  method,  and  operation. 
The  term  "art"  is  ambiguous  in  popular  usage.     In  the  phrase  "useful  arts"  in  the  Constitution,  it  denotes 
the  area  of  endeavor  to  which  the  patent  laws  apply.    When  the  word  "art"  is  used  to  specify  some  frag- 
ment of  the  useful  arts,  it  commonly  raises  different  notions  in  different  minds.    It  may  be  correctly  used 
to  designate  any  division  of  the  useful  arts.     It  is  as  proper  to  speak  of  the  art  of  grinding  or  the  art  of 
molding  as  of  the  art  of  metal-working  or  the  art  of  brickmaking. 

2  A  "use"  is  an  application  of  a  means  to  substance  to  produce  an  effect  which  may  or  may  not  be  the 
necessary  effect  of  the  means  in  its  normal  operation.    A  catalytic  may  be  used  to  ignite  gas  or  to  con- 
vert oleins  into  stearines.    Ani  ce  pick  may  be  used  to  hold  a  chalk  line  or  prick  holes  in  leather,  etc. 


6  CLASSIFICATION    OF   PATENTS. 

similar  results  by  the  application  of  similar  natural  laws1  to  similar 
substances. 

As  all  inventions  are  made  with  the  ultimate  object  of  satisfying 
some  human  desire,  the  utility  of  an  invention  appears  to  be  a  natural 
basis  of  classification.  It  is  apparent,  however,  that  most  inventions 
may  contribute  to  numerous  utilities  besides  the  ultimate  one.  Many 
processes  and  instruments  intervene  between  the  seed  planter  and 
the  wheaten  rolls  upon  the  breakfast  table.  The  plow  may  be  viewed 
as  an  agricultural  instrument  or  as  an  instrument  of  civil  engineering, 
according  as  it  is  used  for  preparing  the  field  for  planting  or  round- 
ing a  road.  A  radiating  coil  of  pipe  may  be  thought  of  as  a  condenser 
of  steam  or  of  alcoholic  vapors,  according  as  it  is  applied  to  one  mate- 
rial or  another;  as  a  cooler  or  a  heater,  according  to  the  temperature  of 
a  fluid  circulated  through  it.  A  hammer  may  drive  nails,  forge  iron, 
crack  stone  or  nuts.  Underlying  all  of  these  ulterior  utilities,  there 
is  a  fundamental  one  to  which  the  normal  mind  will  reach  in  its 
natural  processes  and  there  rest.  The  plow  loosens  or  turns  over  the 
surface  of  earth;  the  coil  effects  an  exchange  of  heat  between  its  in- 
terior and  exterior;  the  hammer  strikes  a  blow.  A  classification  of 
plows  in  agriculture,  road  building,  or  excavating,  according  to  stated 
ultimate  use;  of  a  radiator  coil  as  a  steam  condenser,  still,  jacket- 
water  cooler,  refrigerator,  or  house  heater;  of  the  hammer  as  a  forg- 
ing tool,  a  nail  driver,  or  a  nut  cracker,  appears  to  separate  things 
that  are  essentially  alike.  But  classifying  a  plow  on  its  necessary 
function  of  plowing,  a  radiator  on  its  necessary  function  of  exchang- 
ing heat,  a  hammer  on  its  necessary  function  of  striking  a  blow,  evi- 
dently results  in  getting  very  similar  things  together.  Assuming  for 
the  moment  that  utility  is  a  reasonable  basis  of  division  of  the  useful 
arts,  it  is  deemed  more  logical  to  adopt  as  a  basis  some  utility  that 
must  be  effected  by  the  means  under  consideration  when  put  to  its 
normal  use  rather  than  some  utility  that  may  be  effected  under  some 
conditions.  Two  of  the  five  predicables  of  ancient  logic  are  property 2 
and  accident.3  The  capacity  of  the  hammer  to  strike  a  blow,  the 
capacity  of  the  radiator  coil  to  exchange  heat,  are  in  the  nature  of 
properties.  The  capacity  of  the  hammer  to  crack  nuts,  of  the  coil  to 
condense  steam,  are  in  the  nature  of  accidents — something  that  follows 

*By  "natural  law"  in  the  usefu  1  arts  is  meant  that  uniformity  of  action  which  is  manifested  whenever 
any  particular  substance  in  any  particular  condition  is  brought  into  such  relation  with  any  particular 
manifestation  of  energy  that  the  force  exerted  modifies  or  prevents  modification  of  the  form,  nature,  con- 
dition, or  locus  of  the  substance  or  modifies  the  manifestation  of  energy  or  both. 

*  A  "property"  may  be  described  as  any  quality  common  and  essential  to  the  whole  of  a  class  but  not 
necessary  to  mark  out  that  class  from  other  classes.  Thus,  all  wheel  tires  may  be  said  to  possess  annu- 
larity;  but  washers  and  finger  rings  are  also  annular.  A  "peculiar  property"  is  one  that  not  only  always 
belongs  to  a  class  of  objects  but  belongs  to  that  class  alone;  thus  a  circle  has  the  peculiar  property  of  con- 
taining the  greatest  space  within  a  line  of  given  length,  and  catalytic  substances  have  the  power  of  setting 
up  chemical  reaction  without  themselves  being  changed. 

'  An  "accident"  is  any  quality  that  may  indifferently  belong  or  not  belong  to  a  class  without  affecting 
the  other  qualities  of  the  class.  That  a  man's  name  is  James  is  an  accident  telling  nothing  of  the  man's 
physique  or  character. 


CLASSIFICATION    OF   PATENTS.  7 

from  the  impact  and  the  heat  exchange  because  of  the  particular 
accidental  conditions  of  operation.  To  select  an  accident  as  a  basis 
of  classification  is  contrary  to  the  laws  of  thought. 

It  may  be  said  then  that  the  Patent  Office  classification  is  based 
upon  "art"  in  the  strict  sense  in  which  the  word  may  be  said  to  be 
used  in  section  4886,  Revised  Statutes,  but  not  necessarily  in  the 
looser  sense  of  industries  and  trades.  A  proper  maintenance  of  the 
distinction  between  the  word  " arts"  of  the  statute  and  the  phrase 
11  industrial  arts"  used  in  the  sense  of  industries  and  trades  is  essential 
to  an  effective  classification  for  the  purposes  of  a  patent  office  search. 
Similar  instruments  have  been  patented  in  three  different  classes,  be- 
cause of  the  statements  that  one  was  designed  for  cooling  water,  an- 
other for  heating  water,  another  for  sterilizing  milk;  in  four  different 
classes,  because  of  the  statements  that  one  apparatus  was  to  separate 
solids  from  the  gases  discharged  from  a  metallurgical  furnace,  an- 
other to  separate  carbon  from  the  combustion  gases  of  a  steam-boiler 
furnace,  another  ,to  remove  dust  and  tar  from  combustible  gas,  and 
another  to  saturate  water  with  carbon  dioxid.  Owing  to  the  con- 
tinuance of  a  classification  based  largely  on  remote  use,  many  appli- 
cations come  into  the  office  setting  forth  inventions  of  very  general 
application  which  nevertheless  have  to  be  classified  more  or  less  arbi- 
trarily in  one  of  several  arts  in  which  they  may  be  used  but  to  which 
they  are  not  limited. 

Function  or  effect  as  a  basis.1 — Means  of  the  useful  arts  are  related  in 
different  degrees.  Resemblances  selected  as  bonds  for  a  number  of 
inventions  may  be  more  or  less  close.  It  is  axiomatic  that  close  re- 
semblances should  be  preferred  over  looser  ones  for  classification  pur- 
poses. Processes  and  instruments  for  performing  general  operations, 
such  as  moving,  cutting,  molding,  heating,  treating  liquids  with  gases, 
assembling,  etc.,  are  more  closely  bonded  than  those  for  effecting  the 
diverse  separate  successive  operations  directed  toward  complex 
special  results,  such  as  making  shoes,  buttons,  nails,  etc.  Means  of 
the  former  sort  perform  an  essentially  unitary  act — the  application 
of  a  single  force,  the  taking  advantage  of  a  single  property  of  matter. 
Those  of  the  latter  sort  require  the  application  of  several  different 
acts  employing  frequently  a  plurality  of  forces  or  taking  advantage 
of  several  properties  of  matter.  In  the  former  case,  classification  can 
be  based  on  what  has  been  called  function,  in  the  latter  it  cannot  be 

1  "Effect"  or  " result"  is  the  consequence  of  a  process  of  the  useful  arts  practiced  with  or  without  In- 
struments. The  effect  of  an  instrument  is  the  effect  of  its  operation.  Effects  may  be  direct  or  indirect, 
proximate  or  remote,  necessary  or  accidental. 

"Product"  is  an  effect  consequent  upon  a  process  that  changes  the  form,  state,  or  ingredients  of  matter 
perceptibly  and  permanently,  as  distinguished  from  effects  that  are  fleeting  or  involve  no  change  in  per- 
ceptible form,  state,  or  ingredients  of  matter. 

"Function"  is  the  "action  of  means  upon  an  object  while  producing  the  effect."  (Robinson.)  Func- 
tions may  be  direct  or  indirect,  proximate  or  remote,  necessary  or  accidental.  The  direct,  proximate,  or 
necessary  function  of  the  hammer  in  normal  operation  is  impacting.  Indirect,  remote,  or  accidental  func- 
tions of  a  hammer  may  be  comminuting,  forging,  driving,  etc. 


8  CLASSIFICATION   OF   PATENTS. 

based  on  function  but  can  te  based  on  what  has  been  called  effect 
(or  product). 

Function  is  closely  related  to  cause.  It  is  an  axiom  of  logic  that 
cause  is  preferable  to  effect  as  a  basis  of  those  classifications  designed 
for  scientific  research.  Hence  the  functional  basis  is  preferred  in  all 
cases  in  which  it  can  be  applied.  A  condenser  for  the  fumes  of  zinc 
is  much  more  like  a  condenser  for  the  fumes  of  acid  or  the  vapor  of 
water  than  it  is  like  the  art  of  recovering  zinc  from  its  ores,  and  it 
employs  only  one  principle/ to  wit,  heat  interchange.  A  water-jacket 
for  cooling  the  walls  of  a  gas-producer  or  glass-furnace  is  much  more 
like  a  water-jacket  for  cooling  the  walls  of  a  limekiln  or  steam-boiler 
furnace  than  it  is  like  the  art  of  gas-making  or  manufacture  of  glass 
articles.  In  accordance  with  what  are  thought  to  be  the  correct 
principles,  therefore,  the  zinc-condenser  ought  not  to  be  classified  as  a 
part  of  the  art  of  metallurgy,  nor  the  water-jacket  as  a  part  of  the  art 
of  gas-making,  merely  because  these  instruments  have  a  use  in 
these  arts,  but  should  be  included,  respectively,  in  classes  based  upon 
the  more  fundamental  utilities  effected  by  them. 

Although  it  is  evident  that  molding  a  button  is  more  like  molding  a 
door-knob  than  it  is  like  making  buttons  by  the  combined  operations 
of  sawing,  grinding,  turning,  and  drilling,  wherefore  the  molding  of 
buttons  should  be  classified  in  a  general  plastic  art  rather  than  in  a 
special  button-making  art,  yet  the  making  of  buttons  by  a  plurality 
of  different  kinds  of  operations  can  be  placed  only  in  a  class  based 
upon  the  product,  to  wit,  button-making.  Since,  therefore,  the  com- 
bination of  many  different  operations  for  the  production  of  a  specific 
article  can  not  be  classified  on  the  basis  of  any  single  function,  it  must 
be  classified  on  the  basis  of  product.  Thus  by  selecting  essential 
function  as  a  basis  when  possible,  and  resulting  effect  when  the  func- 
tional basis  is  not  possible,  one  may  approximate  to  the  correct  classi- 
fication described  by  Herbert  Spencer  as  follows:  "A  true  classifica- 
tion includes  in  each  class  those  objects  that  have  more  characteristics 
in  common  with  one  another  than  any  of  them  have  with  objects 
excluded  from  the  class." 1 

So  it  is  deemed  better  to  classify  in  accordance  with  the  function 
or  effect  it  is  known  a  means  must  perform  or  accomplish  than  in 
accordance  with  the  object  with  respect  to  which  an  act  or  acts  are 
directed  or  in  accordance  with  some  effect  which  may  or  may  not  result. 

Structure  as  a  basis. — The  phrase  " structural  classification"  is  fre- 
quently made  use  of.  The  application  of  the  phrase  to  processes  is 
manifestly  absurd.  The  Patent  Office  never  had  a  structural  classi- 
fication except  in  a  limited  sense.  How  could  a  machine,  for  example, 
be  classified  on  structure,  leaving  out  of  consideration  its  function 
and  the  effect  of  its  normal  operation  ?  In  the  refinements  of  sub- 

i  Classification  of  the  Sciences. 


CLASSIFICATION    OF   PATENTS.  9 

division,  however,  it  becomes  frequently  desirable  to  form  minor 
subdivisions  on  structural  differences.  And  it  may  also  be  that 
instruments  will  be  presented  for  classification  that  are  of  such  general 
utility  as  to  baffle  the  efforts  of  the  intellect  to  attain  to  the  funda- 
mental and  necessary  function,  in  which  case  a  structure-defined 
class  may  best  suit  the  needs  of  classification. 

As  between  a  classification  based  upon  structure  and  one  based 
upon  utility,  the  choice  has  been  for  the  latter,  without  prejudice, 
however,  to  instances  that  may  arise  in  favor  of  the  former. 

The  subject  of  structural  classification  will  be  dropped  with  a 
quotation  from  the  original  pamphlet  "Plan  of  Classification/'  etc. 
(p.  5):  "A  purely  'structural'  classification  is  almost  impossible  on 
account  of  the  infinite  variety  of  mechanical  combinations,  and  to 
attempt  it  would  probably  result  in  utter  confusion,  for  the  classes 
could  not  be  defined,  and  the  classification  would  be  a  mere  digest  of 
mechanical  elements  having  no  community  of  function." 

DIVISION    AND   ARRANGEMENT. 

Having  divided  the  aggregate  of  things  to  be  classified  into  a  large 
number  of  groups  on  a  satisfactory  basis,  a  most  useful  work  will  have 
been  accomplished  and  the  purpose  of  a  classification  to  assemble 
the  things  most  nearly  alike  and  separate  them  from  other  things  will 
have  been  partially  achieved.  Unless  these  numerous  groups  are 
arranged  in  some  definite  understandable  relation  to  each  other,  or  art 
placed  in  definite  known  positions  where  they  can  be  found,  the  mere 
formation  of  the  groups,  on  however  good  a  basis,  is  not  a  complete 
classification.  Furthermore,  unless  the  position  of  each  group  with 
respect  to  those  other  groups  that  resemble  it  in  whole  or  in  part  is 
made  known,  he  who  wishes  to  find  other  related  matter  must  seek 
aimlessly  with  no  assurance  that  his  quest  will  end  until  the  whole 
series  shall  have  been  investigated.  Each  classified  group  is  meta- 
phorically a  pigeonhole  to  contain  similar  material.  If  the  pigeon- 
holes are  properly  labeled,  one  can  ultimately  locate  those  that  contain 
the  matter  he  is  seeking  if  he  knows  the  name  that  has  been  applied  to 
it.  If  the  pigeonholes  are  arranged  in  alphabetical  order,  for  example, 
he  may  find  all  related  material,  provided  Tie  knows  the  name  of  every 
related  group  of  material,  even  though  very  similar  things  may  bear 
names  as  far  apart  as  A  and  Z.  But  if  all  things  were  so  placed  that, 
adjacent  and  in  certain  fixed  relation  to  each  pigeonhole,  other  related 
matter  could  be  found,  the  resemblances  lessening  in  proportion  to 
the  separation,  and  if  the  entire  area  of  pigeonholes  were  divided, 
and  certain  areas  assigned  to  certain  kinds  of  things  defined  in  general 
terms,  guessing  the  location  of  and  desultory  search  for  things  that 
may  have  different  names,  but  yet  be  very  much  alike,  would  be  less- 
ened and  all  cognate  material  be  bunched.  A  second  vital  factor  of  a 
system  of  classification,  therefore,  is  the  arrangement  of  the  groups. 


10  CLASSIFICATION    OF   PATENTS. 

Infinitude  of  possible  combinations. — There  are  now  over  1,125,000 
United  States  patents,  each  presumptively  covering  a  creation  of  the 
useful  arts  that  is  different  from  every  other.  Most  of  these  patents 
also  disclose  a  plurality  of  elements  or  acts.  Each  of  these  patented 
means  is  potentially  an  element  of  a  more  complex  combination  that 
may  be  patented.  When  one  considers  merely  the  number  of  forms 
of  energy,  the  number  of  known  substances  and  known  mechanical 
elements,  and  attempts  to  figure  possible  combinations  and  permuta- 
tions, it  becomes  apparent  that  the  size  of  the  numbers  resulting  is 
incomprehensible.  Consider  the  possibilities  of  combination  also  of 
the  enormously  varied  disclosures  of  patents.  Calculations  of  the 
possible  combinations  and  permutations  of  a  small  number  of  objects 
are  familiar.  Different  combinations  of  the  letters  of  the  alphabet 
are  sufficient  to  record  the  sum  of  human  knowledge  in  many  lan- 
guages. With  substantially  two  octaves  of  the  diatonic  scale  the 
world's  melodies  have  been  sounded,  nor  do  any  doubt  that  our 
successors  will  thrill  to  airs  that  we  have  never  heard.  " Thirty 
metals  may  be  combined  into  435  binary  alloys,  4,060  ternary  alloys, 
27,405  quarternary  alloys"  (Jevons).  This  does  not  take  into  con- 
sideration differences  in  proportion  that  figure  so  largely  in  results  in 
the  arts  of  substaDce-making.  The  total  number  of  possible  alloys 
of  the  known  metals  is  incomprehensible.  A  moment's  thought 
respecting  the  numbers  of  the  means  of  the  useful  arts  will  alleviate 
any  fears  that  the  possibilities  of  invention  are  near  the  limit  and 
will  give  food  for  further  thought  to  all  concerned  with  this  attempt 
to  classify  the  useful  arts  to  the  point  of  refinement  necessary  to 
enable  this  office  to  pass  judgment  with  reasonable  speed  and  accuracy 
upon  the  approximately  75,000  applications  filed  each  year. 

Division  and  arrangement  in  the  natural  sciences. — Some  of  the 
natural  sciences  are  said  to  be  in  what  is  known  as  the  classificatory 
stage  of  development.  In  some  sciences  the  subject  of  classification 
has  been  predominant  and  these  furnish  excellent  examples  of  scien- 
tific classification. 

The  much-admired  classifications  of  zoology,  botany,  and  miner- 
alogy are  among  the  best  available  models  of  logical  division,1  sys- 
tematic and  analytical  arrangement.  The  most  casual  consideration 
of  these  classifications,  however,  renders  apparent  the  relative  sim- 
plicity of  the  task  of  classifying  natural  objects  differentiated  by 
fixed  natural  laws  as  compared  with  the  task  of  classifying  the 
products  of  the  creative  and  imaginative  faculties  as  applied  to  the 
useful  arts.  The  chimera  and  other  animal  monsters  occur  only  as 
figments  of  the  mind.  Zoological  classification  does  not  have  to 
classify  combinations  of  birds,  fishes,  reptiles,  and  mammals,  nor 

1  Logical  division  is  the  process  by  which  the  species  of  which  a  genus  is  composed  are  distinguished  and 
set  apart.  Physical  division  or  partition  is  the  process  by  which  the  parts  of  any  object  are  distinguished 
and  set  apart.  Metaphysical  division  is  the  process  by  which  the  qualities  of  a  thing  are  segregated  and 
set  apart  in  thought. 


CLASSIFICATION   OP  PATENTS.  11 

does  it  deal  in  the  way  of  classification  with  the  parts  of  animals, 
nor  is  the  question  of  absolute  numbers  of  instances  a  matter  of 
moment  to  such  a  classification,  all  of  the  members  of  a  species  being 
alike  for  classification  purposes.  But  any  instrument  of  the  useful 
arts  may  be  combined  with  some  other,  any  part  with  some  other 
part.  Organizations  may  be  parts  of  some  other  organizations,  or 
even  mutually  parts  of  each  other,  as,  for  example,  a  pump  may  be  a 
part  of  a  lubricator,  or  a  lubricator  may  be  a  part  of  a  pump.  Some 
parts  are  peculiar  to  one  instrument,  some  are  common  to  many. 
Every  member  of  a  species  differs  from  every  other  member.  Added 
to  this,  the  intellectual  differences  between  the  persons  who  present 
the  applications  for  patent,  the  differences  in  their  generalizing 
powers,  the  relatively  broad  and  narrow  views  of  two  or  more  per- 
sons presenting  the  same  invention  (variations  not  indulged  in  by 
nature)  complicate  the  problem  of  classifying  the  useful  arts. 

Difficulty  of  entitling  a  subclass  corresponding  to  every  combination. — 
In  any  main  class  or  group  of  the  useful  arts  there  are  always  a 
number  of  characteristics  that  it  may  be  desirable  to  take  note  of  in 
subdivision  titles.  A  moment's  thought  shows  the  impossibility  of 
taking  care  of  any  large  number  of  combined  characteristics  so  as  to 
provide  exactly  for  each  combination,  for  the  reason  that  the  limita- 
tions of  space  and  of  the  perceptive  faculties  forbid.  For  a  simple 
illustration,  the  imaginary  classification  of  books  for  use  by  a  book- 
seller may  be  recurred  to.  The  dealer,  it  may  be  assumed,  has  books 
on  (1)  four  different  subjects,  history,  science,  art,  and  fiction,  (2) 
each  printed  in  four  languages,  English,  German,  French,  Spanish, 

(3)  in  four  different  sizes  of  page,  folio,  quarto,  octavo,  duodecimo, 

(4)  bound  in  four  materials,  leather,  rawhide,  cloth,  paper.     Here 
are  four  main  characteristics,  each  in  four  varieties.     A  customer  is 
likely  to  ask  for  Ivanhoe  in  English,  octavo,  bound  in  leather.     Now 
if  the  bookseller  had  sought  to  arrange  the  books  into  one  class  ac- 
cording to  subject  matter,  into  another  according  to  language,  an- 
other according  to  size,  another  according  to  binding,  he  would  have 
fallen  into  confusion,  because  his  classes  would  be  formed  on  different 
principles  or  bases  and  overlap.     Some  histories  will  be  in  French, 
some  will  have  octavo  pages,  and  some  cloth  bindings.     But  if  he 
divides  first  on  the  basis  of  subject  matter,  then  each  subject  matter 
into  language,  each  language  book  into  sizes,  each  size  into  material 
of  binding,  he  can  immediately  place  his  hand  on  a  class  wherein  the 
book  will  be  if  he  has  it;  but  this  classification,  based  on  four  dif. 
ferent  characteristics  and  four  varieties  of  each,  has  necessitated  the 
formation  of  256  classes  or  divisions,  and  if  five  characteristics  were 
provided  for,  1,024  divisions  would  be  required. 

Adapting  the  illustration  of  the  books  to  a  patent  office  classi- 
fication: If  it  were  possible  to  view  these  characteristics  as  patentable 

79163-15 3 


12  CLASSIFICATION  OF  PATENTS. 

in  combinations  of  all  or  in  any  combinations  less  than  all,  and  also 
as  separate  characteristics,  16  divisions  additional  to  the  256  for 
each  independent  characteristic  would  have  to  be  provided,  as  well 
as  other  divisions  for  combinations  of  less  than  the  whole,  in  order 
to  make  the  classification  absolutely  indicative  of  every  feature, 
and  the  number  of  divisions  would  be  enormous.  In  such  a  classi- 
fication, after  the  proper  division  had  been  located,  the  search 
would  be  nothing,  the  difficulty  would  be  to  find  the  appropriate 
class. 

Expedients  to  reduce  the  number  of  subdivisions. — Fortunately  most 
people  carry  on  their  mental  processes  in  accordance  with  certain 
uniformities.  Under  this  uniformity  of  thought  no  patent  able 
relationship  may  be  alleged  between  a  quarto  volume  and  the  subject 
of  history  or  between  a  leather  binding  and  the  German  language; 
wherefore  4  classes  of  coordinate  value,  based  on  the  4  characteristics, 
each  divided  into  4  subclasses,  16  divisions  in  all,  may  serve  the 
purpose  of  a  Patent  Office  search.  But  if,  as  sometimes  happens, 
a  patentable  relationship  had  been  assumed  and  admitted  between 
a  leather  binding  and  any  of  the  languages,  or  any  of  the  subjects,  or 
between  any  two  or  more  of  those  different  characteristics,  provi- 
sion could  be  made  for  such  combinations  by  the  following  expedients : 

(1)  Arrange  the  characteristics,  in  the  order  of  relative  signifi- 
cance or  importance  for  the  purpose  in  view,  in  four  groups,  giving 
each  group  the  characteristic  title.  Under  each  title  arrange  the 
varieties  in  a  similar  relation  as  follows  in  either  (1)  or  (2): 

(1)  (2) 

Cl.  X.— BOOKS.  Cl.  X.— BOOKS. 

0.      Miscellaneous.  1.  Subject-matter — 

0.5    Subject-matter —  2.      History. 

1.  History.  3.      Science. 

2.  Science.  4.      Art. 

3.  Art.  5.      Fiction. 

4.  Fiction —  6.  Language — 
4.5    Language —  7.      English. 

5.  English.  8.      German. 

6.  German.  9.      French. 

7.  French.  10.      Spanish. 

8.  Spanish.  11.  Size— 
8.5  Size—  12.      Folio. 

9.  Folio.  13.      Quarto. 

10.  Quarto.  14.  Octavo. 

11.  Octavo.  15.  Duodecimo. 

12.  Duodecimo.  16.  Binding — 
12.5  Binding  material —  17.  Leather. 

13.  Leather.  18.  Rawhide. 

14.  Rawhide.  19.  Cloth. 

15.  Cloth.  20.  Paper. 

16.  Paper. 


CLASSIFICATION    OF   PATENTS.  13 

Subject-matter,  assumed  to  be  the  most  important  characteristic, 
is  placed  first.  Any  exhibit  of  mere  material  for  binding,  mere  size, 
mere  language,  or  mere  subject-matter,  would  fall  into  the  corre- 
spondingly entitled  group.  If,  however,  a  book  on  history  in  Ger- 
man or  a  history  in  red  leather,  etc.,  were  to  be  classified,  it  would 
be  placed  in  subclass  " History"  in  the  subject-matter  group,  and  a 
French  book  in  green  cloth  would  be. placed  in  subclass  " French"  in 
the  language  group.  That  is,  combinations  of  any  characteristic  with 
any  one  or  more  other  characteristics  may  be  placed  in  the  group 
for  that  characteristic  deemed  the  most  significant  and  which  is 
highest  in  the  schedule.  Again,  by  assigning  a  number  to  each 
generic  title,  each  such  title  becomes  thereby  the  miscellaneous  group 
for  varieties  other  than  those  indented  under  it,  as  well  as  for  all 
varieties  associating  any  characteristic  with  one  or  more  of  those 
standing  lower  down.  Thus,  a  book  of  poems  would  belong  hi 
subclass  " Subject-matter"  and  a  16mo  volume  bound  with  purple 
celluloid  covers  would  belong  in  subclass  "Size."  So,  by  giving 
meaning  to  relative  position,  exhaustive  arrangement  is  sought  to 
be  provided  in  a  reasonable  number  of  groups.  To  provide  for  other 
features  that  may  be  presented  in  future,  an  additional  miscella- 
neous group  may  be  added  at  the  top  (1),  or  the  class  title  (2)  might 
be  deemed  to  represent  the  unclassified  residue  and  a  depository  for 
future  matter  not  specifically  provided  for. 

(2)  If  the  number  of  instances  of  association  of  subject-matter  and 
binding  materials,  language  and  size,  etc.,  are  numerous,  additional 
groups  might  be  placed  above  the  groups  having  the  names  of  the 
characteristics,  the  fact  of  the  existence  of  these  groups  indicating 
that  the  characteristic  groups  are  for  single  characteristics  only  and 
do  not  include  books  having  several  different  ones.  In  such  case  the 
schedule  might  be  headed  by  a  miscellaneous  group,  having  either  the 
title  "Miscellaneous"  or  the  title  of  the  class,  to  receive  associated 
characteristics  not  provided  for  by  specific  titles,  immediately  fol- 
lowed by  subclasses  for  the  particular  associations  found  to  be  most 
numerous,  as  follows: 

BOOKS. 

Miscellaneous. 

Subject-matter  and  language. 

Subject-matter  and  binding  material. 

Subject-matter. 

Language. 

Size. 

Binding  material. 

To  illustrate  further,  selecting  for  the  purpose  a  mass  of  objects 
presenting  problems  more  nearly  like  those  presented  to  the  office  in 


14  CLASSIFICATION   OF  PATENTS. 

questions  of  patentability,  let  it  be  assumed  that  one  is  to  classify 
the  objects  in  a  heap  of  metal  scrap. 

On  looking  over  the  material  of  the  heap  it  is  noticed  that  there 
are  a  large  number  of  metal  balls;  some  have  holes  through  them, 
some  are  hollow,  some  are  smooth  on  the  outside,  and  some  are 
hollow,  smooth,  and  perforated,  but  they  are  all  nevertheless  balls, 
and  accordingly  all  balls  can  be  separated  out  and  placed  in  a  heap 
by  themselves.  Next,  the  presence  of  bars  in  the  general  mass  is 
observed,  some  long,  some  short,  some  straight,  some  twisted,  some 
of  round  stock,  some  of  square  stock,  etc.  These  may  be  gathered 
together  and  placed  in  a  separate  pile  at  the  left  of  the  balls.  It  is 
further  observed  that  there  are  many  differently  shaped  annular 
bodies  hi  the  heap  resembling  generally  the  single  links  of  a  chain, 
some  circular,  some  elliptical,  some  twisted,  some  made  of  round 
stock,  some  of  square  stock,  etc.  They  are  all  nevertheless  annular 
bodies;  these  may  be  placed  in  a  separate  pile  at  the  left  of  the  bars. 

Now,  in  the  remnant  of  the  original  heap,  a  sufficient  number  of 
similar  single  elements  does  not  remain  from  which  to  make  a  smaller 
pile  of  elements.  Different  combinations  of  links,  balls,  and  bars 
are,  however,  observed  in  the  remaining  heap.  Some  are  combi- 
nations of  links,  some  combinations  of  a  ball  and  link,  some  of  a  bar 
and  link,  and  some  of  a  bar,  link;  and  ball.  These  different  combi- 
nations may  be  separated  out  in  the  order  named  and  placed  in 
separate  piles.  After  all  these  things  have  been  removed,  there  is 
left  in  the  original  heap  a  number  of  odds  and  ends  or  miscellaneous 
metal  objects. 

These  several  groups  may  now  be  arranged  in  the  inverse  order  in 
which  (hi  the  particular  illustration  adopted)  they  have  been  re- 
moved, thus: 

1.  Miscellaneous  (remnants  of  the  original  heap  of  scrap). 

2.  Combined  bar,  link,  and  ball. 

3.  Combined  bar  and  link. 

4.  Combined  bar  and  ball. 

5.  Combined  link  and  ball. 

6.  Chains. 

7.  Links. 

8.  Bars. 

9.  Balls. 

Knowing  that  objects  of  metal  scrap  not  covered  by  the  specific 
titles  will  be  found  in  the  miscellaneous  group,  and  that  the  more 
complex  specifically-named  things  are  to  be  found  first  after  the 
miscellaneous  or  at  the  left  of  the  row  of  piles  of  materials  thus 
separated  and  arranged,  and  the  more  simple  things  and  parts 
farther  to  the  right,  the  particular  piles  to  resort  to  for  the  things 


CLASSIFICATION   OF  PATENTS.  15 

wanted  may  be  definitely  determined.  The  same  processes  may  be 
applied  to  each  of  the  piles.  Thus,  balls,  in  the  above  illustration, 
may  be  divided  into — 

Balls— 

10.  Hollow  perforated. 

11.  Hollow  grooved. 

12.  Hollow. 

13.  Perforated. 

14.  Grooved. 

Again,  the  same  processes  may  be  applied  to  a  mass  of  more 
diversified  junk,  of  which  the  metal  scrap  may  form  one  pile,  rags 
another,  old  bricks  another,  old  timber  another,  and,  still  another, 
timber  having  metal-straps,  bolts,  nails,  etc.,  connected  with  it. 

Superiority  and  inferiority. — In  the  arrangement  of  subclasses  in  a 
class,  those  groups  that  are  related  to  each  other  as  wholes  and  parts 
are  arranged  so  that  the  wholes  shall  stand  before  the  parts,  and  so 
that  subclasses  defined  by  effect  or  by  special  use  shall  stand  before 
those  defined  by  function  or  general  use.  For  example,  in  the  scrap 
illustration  above,  assuming  the  titles  to  be  in  a  printed  arrangement, 
" chains"  precedes  " links,"  which  may  be  parts  of  chains,  and  if  it 
had  been  desired  to  separate  animal-drags,  for  instance,  from  the 
scrap,  some  animal-drags  being  particular  adaptations  of  a  bar,  links, 
and  ball,  the  group  of  animal-drags  should  precede  "Bar,  link,  and 
ball."  The  words  " superior"  and  " inferior"  have  been  used  to  indi- 
cate this  relationship.  A  class  or  subclass  defined  to  receive  a  certain 
combination  is  superior  to  one  defined  to  receive  an  element  or  a 
combination  that  is  a  part  of  that  certain  combination.  A  class  or 
subclass  defined  to  receive  means  for  making  a  particular  product,  as 
an  electric  lamp,  is  superior  to  a  class  or  subclass  designed  to  perform 
a  general  function,  as  pumping  air  from  a  container.  And  whenever 
a  question  of  assignment  of  a  patent  or  application  that  contains 
matters  of  two  or  more  groups  bearing  that  relation  is  raised,  the 
"superior"  group  is  selected  to  receive  it. 

Further,  in  those  instances  in  which  groups  are  formed  on  different 
bases  or  different  characteristics,  not  comparable  with  each  other, 
and  a  patent  is  presented  having  matter  falling  in  each  group,  that 
group  which  is  highest  in  position  is  preferred  in  those  instances 
where  separate  provision  for  means  having  both  characteristics  has 
not  been  made. 

In  cases  of  necessity,  as  where  a  combination  is  presented  for 
which  no  class  has  been  definitely  provided,  but  classes  exist  into 
which  the  several  parts  would  fall  if  separately  claimed,  the  same 
practice  that  obtains  in  similar  situations  with  respect  to  two  or 
more  subclasses  of  a  class  may  be  followed  with  respect  to  two  or 


16  CLASSIFICATION    OF   PATENTS. 

more  classes  and  the  patent  placed  in  that  class  which,  in  accordance 
with  above-stated  principles,  should  be  deemed  the  " superior." 

Definite  positional  relationship  of  subdivisions. — In  the  metal  scrap 
example,  above,  division  has  been  effected  on  the  one  basis  of  form 
or  contour.  If  it  had  been  desired  to  separate  also  on  material,  for 
example,  if  it  were  deemed  important  to  locate  all  brass  scrap,  each 
of  the  groups  based  upon  form  could  be  divided  into  one  of  brass  and 
one  not  brass,  or  the  entire  heap  could  be  divided  into  brass  and  not 
brass,  and  under  the  heading  " brass"  could  be  indented  the  various 
articles  made  of  brass,  and  under  "not  brass"  the  various  articles  not 
made  of  brass,  and  this  would  double  the  number  of  divisions.  If 
also  it  were  desired  to  separate  the  lead  articles  in  the  same  manner 
the  number  of  classes  would  be  tripled.  Eut,  as  in  the  book  illus- 
tration, it  may  be  impracticable  thus  to  multiply  subdivisions,  and 
the  basis  "form"  having  been  selected  as  of  first-rank  importance,  all 
divisions  based  upon  form  should  be  completed  and  kept  together. 
Then,  "material,"  having  been  selected  as  of  second-rank  importance, 
should  be  carried  out  with  respect  to  all  objects  in  which  form  is  non- 
essential.  If  enough  brass  balls  were  found  to  render  it  advisable  to 
make  a  subdivision  of  them,  they  should  be  assembled  into  a  sub- 
class indented  under  "balls"  and  not  into  a  subclass  indented  under 
"  brass."  Having  selected  one  basis  as  primary,  it  should  never 
subsequently  be  madev  secondary  or  vice  versa.  Some  such  restriction 
on  modes  of  division  appears  salutary  in  a  system  of  divisions  designed 
to  definitely  limit  search.  The  arrangement  herein  sought  to  be 
explained  is  susceptible  of  use  to  limit  all  searches  for  a  single  defi- 
nitely stated  invention  to  a  subclass  properly  entitled  to  receive  it 
or  those  indented  under  it,  and  to  .those  subclasses  above,  which 
may  include  it  as  a  part  of  an  organization  or  specialized  means. 

As  between  coordinate  groups  divided  on  the  same  basis,  there  is 
no  question  of  superiority  and  inferiority.  The  terms  "superior"  and 
"inferior"  are  useful  in  questions  of  relationship  between  combina- 
tions and  subcombinations  or  elements  thereof,  and  between  groups 
founded  on  effect  or  product  and  those  founded  on  simple  function. 
The  mere  difference  in  complexity  of  mutually  exclusive  coordinate 
groups  involves  no  relationship  of  superiority  or  inferiority.  A  sub- 
class to  receive  a  screw-cutting  lathe  is  superior  to  a  subclass  to 
receive  a  lathe-headstock,  a  locomotive  class  is  superior  to  a  class  to 
receive  steam-engines,  for  the  reason  that  the  lathe  is  a  whole  of 
which  the  headstock  is  a  part,  and  the  locomotive  is  an  organization 
of  which  the  engine  is  an  element.  But  the  headstock  subclass  is 
not  superior  necessarily  to  the  tailstock  subclass  simply  because  the 
headstock  is  commonly  more  complex  than  the  tailstock.  Yet  arbi- 
trary preference  for  classification  in  the  headstock  subclass  may  be 


CLASSIFICATION    OF   PATENTS.  17 

established  by  position  where  an  application  or  a  patent  contains 
claims  for  both. 

Thus  in  a  class  that  is  founded  on  a  well-chosen  basis  that  brings 
together  things  bearing  close  resemblances  to  each  other,  all  types 
that  contain  the  elements  essential  to  produce  a  complete  practically 
operative  means  will  be  found  in  subclasses  that  have  a  position 
somewhere  between  the  beginning  and  end  of  the  list  of  subclasses  of 
the  class.  Those  that  add  features  of  elaboration  of  the  essential 
types  aid  those  that  are  highly  specialized  to  some  particular  pur- 
pose within  ohe  definition  of  the  class  will  stand  above  the  essential 
type  subclasses,  while  those  subclasses  for  parts  and  details  will 
stand  below  those  for  the  essential  types. 

Indented  schedules. — In  an  indented  schedule  all  subclasses  in  the 
first  column  reading  from  the  left  are  species  to  the  genus  repre- 
sented by  the  class  title.1  All  subclasses  indented  under  another  sub- 
class are  species  to  the  genus  represented  by  the  subclass  under 
which  they  are  indented.  If  a  title  has  no  number,  it  represents 
merely  a  subject-matter  to  be  divided,  a  genus, — having  no  represent- 
atives except  in  the  species  under  it.  If  a  subclass  having  a  generic 
title  has  a  number,  it  not  only  represents  a  subject-matter  to  be 
divided  hi  to  species  but  also  all  other  species  not  falling  within  the 
titles  indented.  Although  these  relative  positions  might  imply  that 
only  proximate  species  are  indented  one  place,  yet  mechanical  diffi- 
culties render  it  impracticable  to  so  arrange  that  all  species  shall  be 
indented  under  their  proximate  genera. 

Indention  properly  carried  out  has  a  tendency  to  prevent  in  the 
process  ol  logical  division  the  logical  fault  of  proceeding  from  a  high 
or  broad  genus  to  a  low  or  narrow  species.  This  latter  fault  may 
inadvertently  separate  things  that  belong  together.  If,  for  example, 
it  were  desired  to  divide  balls  in  the  stated  illustration  according  to 
material,  an  immediate  division  of  balls  into  aluminum,  zinc,  glass, 

1  Any  class  of  objects  may  be  called  a  "genus"  if  it  be  regarded  as  made  up  of  two  or  more  different  kinds 
of  objects  or  of  two  or  more  species.  "Motors"  is  a  genus  when  the  class  "Motors"  is  considered  as  divided 
into  electric  motors  and  nonelectric  motors,  or  electric  motors,  spring  motors,  weight  motors,  current  motors 
fluid  pressure  motors,  etc.  A  genus  is  more  extensive  than  any  of  its  species  but  less  intensive. 

A  "species"  is  any  class  that  is  regarded  as  forming  a  part  of  the  next  larger  class,  "electric  motors" 
being  a  species  of  "motors"  and  "motors"  being  a  species  of  "energy  transformers."  A  species  is  more 
intensive  than  the  genus  to  which  it  belongs  but  less  extensive. 

Every  species  may  be  a  genus  to  another  species  until  no  further  subdivisions  can  be  made.  This  last 
indivisible  species  is  termed  the  infima  species.  Every  genus  may  be  a  species  to  another  genus  until  a 
point  is  reached  where  no  further  generalization  may  be  made  or  the  summum  genus  is  attained.  In  the 
Patent  Office  classification  of  the  useful  arts,  the  summum  genus  is  useful  arts.  The  summum  genus 
of  the  plastic  arts  would  be  plastics.  The  infima  species  in  the  useful  arts  evidently  never  can  be  attained. 

"Proximate  species"  and  "proximate  genus"  indicate,  respectively,  those  species  that  are  divided  from 
a  genus  without  intermediate  genera,  and  those  genera  from  which  the  species  are  directly  divided.  Motors> 
and  not  energy  transformers,  is  the  proximate  genus  to  the  species,  fluid  motors,  electric  motors,  etc.,  while 
fluid  motors,  electric  motors,  etc.,  and  not  steam  engines,  alternating  current  motors,  etc.,  are  proximate 
species  to  motors. 


18  CLASSIFICATION    OF   PATENTS. 

ivory,  rubber,  would  be  less    useful    than  to  divide  into  mineral 
materials  and  nonmineral  materials  as  follows: 

Balls- 
Mineral — 

Nonmetallic — 

Glass. 
Metallic- 
Aluminum. 
Zinc. 

Nonmineral — 
Vegetable- 
Rubber. 
Animal — 
Ivory. 

However,  it  is  evident  that  indention  carried  to  its  full  extent, 
useful  as  it  is  in  keeping  analogous  things  together,  would  make  the 
printing  of  schedules  complex  and  unwieldy.  Nevertheless,  in  the 
generalizing  process  necessary  in  logical  division  and  arrangement, 
the  divisions  of  species  should  always  be  mentally  indented,  as  it  were, 
under  their  proximate  genera.  Thus,  under  a  genus  unnamed  may  be 
arranged  several  species  in  juxtaposition,  without  actually  printing 
the  name  of  the  genus,  so  that  the  schedule  above  may  read: 

Balls- 
Glass. 

Aluminum . 
Zinc. 
Rubber. 
Ivory. 

In  an  arrangement  printed  in  idea-order,  though  relegating  the 
genera  mineral,  nonmetallic,  metallic,  nonmineral,  vegetable,  animal, 
to  the  mind  unaided  by  printed  words,  the  different  species  of  the 
same  genus  may  be  kept  together  except  that  species  for  which  no 
title  has  been  provided  must  go  back  to  the  subclass  under  which  the 
named  species  are  indented.  Thus  the  arrangement  above  necessi- 
tates placing  in  subdivision  "  Balls  "  all  copper  balls,  whereas  indention 
under  proximate  genus  " metal"  would  have  brought  all  metal  balls 
together.  In  a  finely  divided  classification,  printing  of  titles  for  all 
genera  is  not  practicable;  hence  great  care  ought  to  be  directed  toward 
grouping  species  according  to  the  principles  of  arrangement  herein 
outlined,  noting  that  whenever  a  change  of  basis  is  made,  a  new  genus 
is  implied,  and  that  subclasses  for  all  other  species  of  the  same  genus, 
under  whatever  name,  must  be  brought  into  juxtaposition  as  if  in- 
dented under  the  implied  genus.1 

i  In  the  Manual  of  Classification  of  the  U.  S.  Patent  Office  the  arrangement  of  subclasses  has  always 
been  alphabetical,  although  in  the  Supplement  containing  definitions  of  revised  classes  the  arrangement 
Is  numerical.  If  the  latter  schedule  of  "Balls"  in  the  text  had  been  printed  in  alphabetical  order,  it  is 
apparent  that  the  species  "Aluminum"  and  "Zinc"  of  the  genus  Metal  would  be  as  widely  separated  as 
possible.  In  the  former  schedule  of  "Balls,"  in  which  the  genus  Metal  is  printed,  "Aluminum"  and 
"Zinc"  come  together.  It  is  apparent  that  in  an  alphabetical  arrangement  allied  species  can  not  be  kept 
together  without  printing  every  proximate  genus.  This  fact,  among  others,  indicates  the  advisability 
of  abandoning  the  alphabetical  arrangement  in  the  classification  manual  and  adopting  the  idea  arrange- 
ment in  the  schedules  of  revised  classes,  supplemented  by  a  consolidated  alphabetical  index  of  all  sub- 


CLASSIFICATION   OF  PATENTS.  19 

Bifurcate  division. — Most  discussions  of  classification  make  refer- 
ence to  the  so-called  bifurcate  scheme  of  division  as  the  only  one  by 
which  exhaustive  division  can  be  surely  achieved.  This  is  commonly 
illustrated  by  the  ancient  tree  of  Porphyry.  By  this  method  any 
subject  it  is  desired  to  subdivide  is  first  divided  by  writing  the  name 
of  one  selected  species  at  one  branch  and  writing  at  the  other  branch 
the  name  of  the  same  species  prefixed  by  "Not."  Thus  the  Agassiz 
classification  of  living  beings  divides  them  first  into  sensible  and  not 
sensible  (plants).  A  botanical  classification  divides  plants  into 
flowering  and  not  flowering.  A  zoological  classification  divides 
animals  into  vertebrate  and  not  vertebrate.  By  continuing  the 
process  of  division  in  the  same  manner,  the  division  is  obviously 
exhaustive  of  the  subject,  there  being  always  a  negative  subdivision 
to  receive  any  subsequently  created  or  discovered  species.  Although 
bifurcate  division  has  been  ridiculed  by  some,  it  is  agreed  by  highest 
authority  that  it  is  the  only  plan  of  division  by  which  one  can  be 
sure  to  have  a  consistent  place  for  everything,  or  by  which  one  can 
be  certain  that  the  divisions  are  mutually  exclusive.  It  can  be 
demonstrated  that  a  classification  schedule  in  which  the  relation  of 
genera  and  species  is  shown  by  indentions,  if  correctly  formed  on 
the  principles  now  sought  to  be  applied  in  the  revision  of  the  Patent 
Office  classification,  is  susceptible  of  conversion  into  a  tree  of 
Porphyry,  while  unlike  the  latter  it  is  compact  and  wieldy. 

Utility  of  arrangement  according  to  resemblances. — The  expedient  of 
indicating  kinds  of  relationship  between  several  equally  indented 
divisions  by  relative  position  has  the  folio  wing  utility: 

(1)  A  uniform  rule  is  provided,  applicable  to  all  classes,  for  placing 
inventions  that  bear  the  relation  of  whole  to  part  in  subdivisions  before 
those  that  bear  the  relation  of  a  part  to  that  whole,  and  those  that  are 
defined  by  a  particular  effect,  product,  material,  or  use  before  those 
that  are  defined  by  a  function  or  an  operation  applicable  generally 
to  various  effects,  products,  materials,  or  uses;  whereby  that  portion 
of  the  schedule  in  which  any  invention  belonging  to  any  particular 
class  should  be  found  may  be  approached  whether  or  not  the  investi- 
gator knows  the  name  of  the  object  sought  for  or  the  title  of  the 
appropriate  subdivision. 

(2)  The  substantial  impossibility  of  dividing  many  branches  of 
the  useful  arts  exhaustively  into  a  reasonable  number  of  mutually 
exclusive  or  non-overlapping  subclasses  is  compensated  for;  so  that 
when  the  classifier  or  the  searcher  has  an  invention  to  place  or  to 
find  including  two  or  more  different  kinds  of  characteristics,  for  each 
of  which  a  subdivision  is  provided,  but  no  subdivision  for  the  plural 
characteristics,  it  will  be  known  that  the  invention  should  be  in  the 
subclass  for  that  characteristic  which  stands  before  the  subclass  for 
the  other  characteristic. 


20  CLASSIFICATION    OF   PATENTS. 

(3)  It  compensates  for  omission  of  some  generic  titles  that  if  written 
in  the  indented  schedule  would  lengthen  specific  titles  to  a  cumber- 
some extent. 

(4)  It  provides  a  rule  for  cross-referencing  where  several  inven- 
tions are  claimed  bearing  to  each  other  any  of  the  relationships 
indicated  above,  cross-referencing  being  necessary  in  one  direction 
only  where  the  matter  illustrated  is  coextensive  with  the  matter 
claimed. 

(5)  It  definitely  limits  the  field  of  search  for  any  unitary  invention 
in  any  class  so  arranged,  as  no  patented  invention  having  the  limita- 
tions imposed  by  a  unitary  claim  should  be  found  in  any  subclass 
below  the  subclass  properly  defined  to  receive  it  or  those  indented 
under  it.     Parts  of  such  inventions  may  be  found  below  or  following 
this  subclass  in  the  same  class  if  these  parts  are  within  the  class 
definition,  or  elsewhere  in  the  useful  arts  if  not  within  that  defini- 
tion.    The  unitary  invention  may  be  found  in  the  subclass  limited  to 
it  and  certain  subclasses  arranged  above  or  before  it  adapted  to  re- 
ceive organizations  of  which  it  may  be  a  part. 

A  complete  system  of  arrangement  should  comprise  (1)  a  display 
of  the  entire  field  of  the  useful  arts  in  a  manner  to  show  the  relation 
of  the  larger  as  well  as  of  the  smaller  groups, — carrying  the  appro- 
priate relationship  as  far  as  possible  from  the  highest  genera  to  the 
lowest  species,  the  arrangement  being  such  as  would  bring  materials 
most  nearly  alike  into  closest  propinquity  regardless  of  the  names 
they  may  be  called  by.  (2)  Supplementary  to  this  classification 
arrangement  by  ideas  there  should  be  an  alphabetical  index  of  sub- 
class titles,  appropriately  cross  indexed,  and  additional  titles  of 
various  technical  and  trade  names  of  things  classified  under  subclass 
titles. 

DEFINITION. 

Definition  is  indispensable  in  any  classification  and  is  very  difficult. 
Every  class  must  be  defined  and  all  of  the  groups  under  it.  After 
definitions  have  been  made  and  printed,  they  are  sometimes  found 
inadequate  and  must  be  supplemented  by  the  definitions  of  other 
classes.  This  is  unavoidable  while  the  complete  material  remains 
unexplored.  Definition  in  the  strict  logical  sense  is  not  to  be  expected, 
nor  is  it  necessary.  It  is  commonly  sufficient  if  an  explanation  or 
comparison  be  made  sufficient  to  direct  the  mind  to  the  character  of 
the  contents  of  the  group  and  indicate  its  limitations.  Hitherto  four 
of  the  five  predicables  of  ancient  logic  have  been  mentioned,  to  wit, 
genus,  species,  property,  and  accident.  In  connection  with  definition, 
the  fifth  predicable,  difference,  is  useful.  To  define  a  class,  it  is  suffi- 
cient, generally,  for  the  purposes  of  office  classification,  to  state  a 
peculiar  property  (not  an  accident)  of  the  objects  included  in  the 


CLASSIFICATION    OF   PATENTS.  21 

class;  and *to  define  a  species  under  the  class  it  is  sufficient  to  state 
the  name  of  the  class  plus  the  difference — i.  e.,  with  the  addition  of  the 
limitations  that  characterize  the  species.1  This  procedure  in  defini- 
tion is  susceptible  of  application  from  the  highest  genus  to  the  lowest 
species.  It  is  advisable  to  define  the  means  included  within  a  title 
without  any  introductory  words,  such  as  "this  subclass  includes 
inventions  relating  to,"  etc.,  treating  the  subclass  for  definition  pur- 
poses as  if  it  were  a  collection  of  concrete  things,  in  the  same  manner 
as  in  a  dictionary  definition. 

CROSS-REFERENCES   AND   SEARCH-NOTES.2 

If  patents  were  in  all  respects  like  material  objects,  cross-references 
and  search-notes  would  not  be  necessary.  Nails,  screws,  locks, 
hinges,  and  boxes  are  distinct  things  susceptible  of  definite  separa- 
tion and  classification.  Even  though  nails,  screws,  locks,  and  hinges 
form  part  of  the  box,  the  box  is  still  a  box,  not  a  nail,  screw,  hinge,  or 
lock.  For  the  needs  of  the  Patent  Office  classification,  however, 
although  a  patent  for  a  box  must  be  classified  with  boxes,  yet  if  a 
peculiar  nail,  screw,  lock,  or  hinge  is  claimed  in  the  same  patent  with 
the  box,  or  even  if  any  one  of  these  customary  accessories  of  boxes  is 
illustrated,  it  may  be  necessary  to  provide  copies  of  the  patent  for  the 
box  in  each  of  the  several  classes  provided  for  nails,  screws,  locks, 
or  hinges. 

Inasmuch  as  every  relatively  complex  thing  is  made  up  of  relatively 
simple  things,  it  is  obvious  that  all  disclosures  can  not  be  cross- 
referenced.  Any  attempt  to  calculate  the  number  of  cross-references 
to  be  supplied  if  all  disclosures  of  the  subjects  of  invention  were  to  be 
cross-referenced  would  show  the  number  to  be  incalculable.  It  is 
necessary,  therefore,  to  leave  to  the  judgment  of  the  classifier  the 
propriety  of  cross-referencing  unclaimed  disclosures. 

Should  a  patent  contain  a  number  of  claims  defining  a  number  of 
differently  classifiable  inventions,  complete  cross-referencing  from 

1  A  species  contains  all  the  qualities  of  the  genus  and  more.    These  additional  qualities  form  the  "differ- 
ence."   The  electric  motor  has  the  qualities  that  are  common  to  motors  and  is  differentiated  by  reason  of 
the  fact  that  electric  energy  is  thereby  converted  to  mechanical  motion. 

2  Classification  of  a  patent  is  said  to  be  "original"  in  the  class  and  subclass  which  receives  the  most  inten- 
sive claimed  disclosure,  and  in  which  the  patent  is  indexed  in  the  official  classification  indexes.    "  Original 
classification"  is  referred  to  as  opposed  to  "classification  by  cross-reference." 

A  "cross-reference"  is  a  copy  of  a  patent  placed  in  a  subclass  other  than  that  in  which  the  classification 
is  made  original,  in  order  to  make  available  for  search  inventions  disclosed  therein  and  additional  to  that 
by  which  the  patent  has  been  diagnosed  and  classified. 

A  "digest  cross-reference"  is  a  cross-reference  formed  from  abstracts  or  extracts  from  a  patent  consisting 
of  illustration  and  text  cut  from  a  photolithograph  of  a  patent  and  mounted. 

A  "search-card"  is  a  sheet  of  the  size  of  a  photolithograph  of  a  patent  placed  with  the  photolithographs 
of  patents  forming  a  subclass  in  the  examining  division  and  public  search  room,  and  containing  sugges- 
tions for  further  search,  and  on  the  copy  for  the  search  room,  a  definition  of  the  subclass. 

"Search  notes"  are  addenda  to  class  and  subclass  definitions  comparing  other  classes  and  subclasses 
with  the  one  defined  and  giving  directions  for  search  when  necessary  to  prosecute  search  beyond  the  defined 
class  or  subclass. 


22  CLASSIFICATION   OP  PATENTS. 

the  class  in  which  the  classification  is  made  original  into  the  other 
appropriate  classes  or  subclasses  should  be  effected,  unless  cross- 
search  notes  or  arrangement  of  subclasses  with  appropriate  titles  may 
be  substituted  to  advantage. 

Cross-referencing  or  cross-search  notes  are  made,  as  a  rule,  from 
combination  class  to  element  class,  but  never  or  very  rarely  from  the 
element  class  to  the  combination  class  in  which  it  may  be  used.  Thus 
cross-referencing  should  normally  be  downward  in  a  schedule  of  sub- 
classes. Search  notes  indicate  parallel  or  otherwise  related  classes 
and  subclasses,  and  those  classes  and  subclasses  in  which  analogous 
structures  having  different  purposes  but  adapted  to  answer  broad 
claims  may  be  found. 

By  arbitrary  rules  of  arrangement  such  as  have  been  referred  to  in 
the  section  dealing  with  division  and  arrangement,  a  search  may 
ordinarily  be  definitely  limited  to  a  certain  number  of  subclasses, 
even  where  cross-references  are  not  made.  In  such  arrangement  any 
given  patent,  if  it  be  directed  to  one  invention,  may  be  searched  in  the 
subclass  within  which  the  definition  places  it  or  subclasses  indented 
under  it,  and  in  certain  subclasses  above,  whose  titles  will  indicate 
that  the  invention  might  be  included  as  a  part  of  the  matter  defined 
to  belong  therein,  but  it  would  never  have  to  be  searched  in  any 
subclass  following  and  not  indented  thereunder. 

DIAGNOSIS  TO  DETERMINE   CLASSIFICAITON. 

Each  patent  and  each  application  discloses  one  or  more  means  of 
the  useful  arts  (using  the  term  " means"  to  cover  both  processes  and 
instruments  in  the  sense  in  which  it  is  used  by  Prof.  Robinson), 
almost  always  more  than  one,  since  most  new  means  are  combina- 
tions of  mechanical  elements  or  acts.  In  some  patents  and  applica- 
tions the  disclosure  is  coextensive  with  that  which  is  claimed;  in 
others  there  is  matter  disclosed  but  not  claimed.  The  unclaimed 
disclosure  may  be  as  valuable  as  the  claimed  disclosure  for  purposes 
of  anticipation,  and  the  classification  must  provide  for  both.  If  the 
claimed  disclosure  belongs  in  one  class  and  the  unclaimed  in  others, 
the  classifier  must  choose  between  two  or  more  classes  that  one 
in  which  the  patent  or  application  shall  be  classified  and  those  into 
which  it  shall  be  cross-referenced. 

Claimed  or  unclaimed  disclosure. — The  claims  of  a  patent  are  the 
statutory  indices  of  that  which  the  applicant  believes  to  be  new, 
they  define  an  invention  that  has  been  searched  by  the  Patent  Office 
and  no  anticipation  discovered  for  it.  Future  action  must  be  based 
on  inductions  from  past  experience;  none  knows  what  the  future 
lines  of  search  will  be;  the  only  guides  for  future  searches  are  the 
searches  of  the  past;  the  evidence  of  past  searches  is  the  claims 


CLASSIFICATION   OF  PATENTS.  23 

of  patents;  they  trace  the  course  of  invention.  Furthermore,  a 
presumption  of  novelty  attaches  to  the  claimed  matter;  no  such  pre- 
sumption attaches  to  the  unclaimed.  The  law  requires  every  patent 
for  improvement  to  show  so  much  of  the  old  as  is  necessary  to  explain 
the  uses  of  the  improvement.  In  practice  much  more  than  that  is 
disclosed.  Questions  as  to  the  proper  placing  of  patents  and  cross- 
references  would  be  diminished  by  the  strict  enforcement  of  Rule  36 
of  the  Rules  of  Practice  requiring  that  the  description  and  the  draw- 
ings, as  well  as  the  claims,  be  confined  to  the  specific  improvement 
and  such  parts  as  necessarily  cooperate  with  it.  In  any  event  both 
the  claimed  disclosure  and  that  which  is  unclaimed  must  be  taken 
care  of,  one  by  cross-reference,  and  the  disclosure  selected  for  cross- 
reference  is  that  to  which  no  presumption  of  novelty  attaches. 

This  practice  of  placing  patents  by  the  claimed  disclosure  is  some- 
times misunderstood.  Its  chief  application  is  in  determining  classifi- 
cation in  case  of  disclosures  involving  a  plurality  of  main  classes. 
Furthermore,  the  mere  letter  of  the  rule  is  not  to  be  applied  in 
preference  to  its  spirit.  Subcombinations  claimed  may  be  placed 
with  the  combinations,  and  in  subordinate  type  subclasses  patents 
must  be  placed  sometimes  by  claimed  and  sometimes  by  not-claimed 
disclosures. 

Diagnosis  of  pending  applications. — What  has  been  said  relates  to 
patents.  The  bearing  of  the  practice  of  adopting  the  claimed  dis- 
closure as  the  basis  of  assignment  of  applications  for  examination 
has  also  to  be  considered. 

Two  pending  applications  claiming  the  same  means  very  commonly 
differ  in  the  kind  and  extent  of  disclosure.  One  application  may 
disclose  several  inventions.  Which  of  the  several  disclosures  shall  be 
selected  as  the  mark  by  which  to  place  the  application  ?  For  instance,, 
the  typical  wire-nail  machine  has  a  wire-feeding  mechanism,  a  shear- 
ing mechanism,  an  upsetting  (forging)  mechanism,  side-serrating 
mechanism,  and  pointing  mechanism;  it  may  also  have  a  counting 
mechanism,  a  packaging  mechanism,  an  electric  motor  on  its  frame 
for  furnishing  power;  and,  in  addition,  numerous  power- transmitting 
and  other  machine  parts,  such  as  bearings,  oil-cups,  safety  appliances, 
etc.  The  applicant  may  have  made  a  complete  new  organization  of 
nail-machine  and  may  seek  a  patent  for  the  total  combination, 
He  may  have  invented  a  new  shearing  mechanism  and  have  chosen 
to  show  it  thus  elaborately  in  the  place  of  use  he  had  in  mind,  or  he 
may  have  designed  a  new  counter  or  a  new  oil-cup"  or  a  new  power 
transmission,  or  even  a  new  motor,  and  have  given  his  invention 
this  elaborate  setting.  The  shears,  the  counter,  the  oil-cup,  the 
power  transmission,  and  the  motor  are  separately  classifiable  in 
widely  separated  classes.  How  shall  the  application  be  diagnosed 
for  determining  its  place  in  the  office  classification?  When  the 


24  CLASSIFICATION   OF  PATENTS. 

specification  and  drawing  disclose  (as  most  of  them  do)  several 
subjects  matter  of  invention,  though  claiming  only  one,  which  of 
those  several  subjects  matter  shall  control  the  classification? 

The  most  natural  procedure,  at  first  thought,  would  be  to  classify 
on  the  totality  of  the  showing,  in  which  case  the  application  for  the 
nail-machine,  supposed  above,  would  be  assigned  to  nail-making. 
But  imagine  the  invention  claimed  by  an  applicant  to  be  the  counter. 
Then  the  examiner  in  charge  of  nail-making  would  have  to  search 
the  class  of  registers  with  which  he  is  not  familiar.  Suppose  appli- 
cant No.  2  files  an  application  for  the  same  counter  which  he  illus- 
trates and  describes  in  connection  with  a  bottle-filling  machine,  and 
that,  classifying  on  the  totality  of  the  showing,  this  goes  to  the 
division  that  has  the  class  of  packaging  liquids.  Now  both  the 
examiners  in  charge  of  bottle-filling  and  nail-making,  knowing  that 
counters  are  classified  in  registers,  search  the  class  of  registers  and 
also  the  pending  applications  in  registers.  After  these  examiners 
have  made  their  searches,  suppose  applicant  No.  3  files  an  applica- 
tion for  the  same  counter,  which  he  says  may  be  used  for  counting 
small  articles  produced  by  automatic  machines.  Perhaps  he  shows 
the  counter  attached  to  a  piece  of  conventional  mechanism  repre- 
senting any  manufacturing  machine,  mentioning,  say,  a  cigarette  or 
pill  or  cartridge-making  machine.  It  has  not  occurred  to  either  the 
the  examiner  of  nail-making  or  the  examiner  of  bottle-filling  that  the 
other  might  have  any  such  application;  nor  does  it  occur  to  the 
examiner  in  charge  of  registers  to  search  nail-making  or  bottle-filling. 
As  the  specification  of  the  counter  application  mentions  cigarette, 
pill,  and  cartridge-making  machines  to  which  the  counter  may  be 
attached,  the  examiner  in  charge  of  registers  may  search  those 
classes.  Suppose  that  the  counter  proves  to  be  new,  and  each  of  the 
three  examiners  allows  a  patent.  Here  now  are  three  patents  for 
the  same  thing.  Of  course,  after  allowance,  the  counter  and  all 
other  disclosed  inventions  that  give  any  suggestion  of  novelty  are 
cross-referenced;  but  the  primary  purpose  of  a  patent  office  classifica- 
tion (to  aid  in  determining  patentability)  has  failed  in  this  instance. 

In  the  imagined  situation  respecting  pending  applications,  without 
doubt  diagnosis  and  classification  upon  the  invention  claimed  is 
necessary  to  effect  the  purpose  of  the  office  classification.  Cross- 
referencing  after  issue  can  not  undo  that  which  has  been  done. 

If  no  applicatipn  save  that  of  the  nail-machine  be  pending,  no 
duplication  of  patents  occurs,  but  the  labor  of  search  is  increased  by 
reason  of  the  unfamiliarity  of  the  examiner  with  the  inventions  he 
has  to  search.  After  the  patent  is  allowed  he  may  find  the  entire 
combination  of  the  nail-machine  without  the  counter  disclosed  in  a 
patent  for  a  nail-making  machine,  so  that  as  a  nail-making  machine 


CLASSIFICATION   OF   PATENTS.  25 

this  new  patent  is  of  no  value  as  a  reference.  Very  probably  all  of 
the  other  inventions  illustrated  (except  the  counter)  are  also  old  in 
their  respective  classes;  but  the  examinei  of  nail-making  can  not 
tell  this  without  extensive  searches  in  those  classes,  so  he  notes  cross- 
references  for  them  all. 

Difficulties  due  to  varying  ideas  of  claims. — Very  troublesome  ques- 
tions are  constantly  arising  as  to  whether  an  invention  should  be 
classified  in  a  combination  class  or  an  element  class.  The  point 
will  be  illustrated  by  example:  A  describes  and  illustrates  an 
automobile  having  an  internal-combustion  motor  and  a  friction- 
clutch  in  the  motor  transmission-gear.  He  states  that  the  clutch  is 
in  the  usual  relationship  to  the  motor  and  gearing,  but  claims  a 
new  clutch  for  whatever  it  may  be  adapted.  B  discloses  an  inter- 
nal-combustion motor  said  to  be  for  automobiles  with  transmis- 
sion-gearing and  a  friction-clutch  and  claims  "in  an  internal-com- 
bustion motor  a  friction-clutch/'  etc.,  specifying  the  form  of  the 
clutch.  C  makes  the  same  disclosure,  but  claims  "an  internal-com- 
bustion motor  having  a  specified  clutch,"  while  D,  with  the  same 
disclosure,  claims  "the  combination  with  the  internal-combustion 
engine  of  an  automobile"  of  a  specified  friction-clutch.  E  claims 
and  illustrates  only  the  friction-clutch.  Should  these  be  classified 
together?  If  so,  in  what  class?  Should  a  bearing  composed  of  a 
specified  alloy  of  copper,  tin,  and  antimony,  be  classed  as  a  bearing  or 
as  an  alloy?  Should  a  house  painted  with  a  mixture  of  linseed  oil, 
lead  oxid,  and  barium  sulphate  go  to  buildings  or  coating  com- 
positions ?  A  lamp-filament  of  titanium  and  zirconium  with  electric 
lamps  or  with  alloys?  A  building-block  of  cement,  lime,  sand, 
and  carborundum,  with  building-blocks  or  plastic  compositions? 
Whether  these  be  diagnosed  as  combinations  or  as  elements  and 
compositions  respectively,  and  classified  accordingly,  criticism  will 
be  aroused.  The  point  in  view  is  that  although  principles  of  patent- 
ability must  be  considered  in  a  classification  designed  as  an  instrument 
to  aid  in  determining  patentability,  convenience  and  accuracy  of 
search  and  avoidance  of  voluminous  cross-referencing  may  neces- 
sitate some  arbitrary  rule  of  classification  to  meet  various  and 
changing  theories  applied  to  the  drafting  and  allowance  of  claims. 

From  the  foregoing  it  will  be  evident  that  classification  involves 
orderly  logical  processes  of  induction  (supplemented  by  hypothesis), 
of  definition  and  of  deduction.  After  gathering  a  large  number  of 
facts  generalizations  are  made  from  them  and  a  hypothesis  is  found 
to  be  confirmed  or  modified  by  more  extended  research;  the  divisions 
are  then  defined;  by  correct  diagnosis  of  other  instances  (as  other 
patents)  deductions  may  be  drawn  respecting  the  appropriate  place 
for  them  in  the  classification. 


26  CLASSIFICATION   OF  PATENTS. 

(C)  RULES  OF  CLASSIFICATION, 

BASIS   OF    CLASSIFICATION. 

(1)  The  basis  of  subdivision  and  assemblage  of  the  means  of  the 
"useful  arts"  in  the  Patent  Office  classification  is  "art"  within  the 
meaning  of  "art'7  in  section  4886,  Revised  Statutes.     The  direct, 
proximate  or  necessary  art,  operation  or  effect,  rather  than  some 
accidental  and  remote  use  or  application,  should  be  selected.     In  all 
cases 'qu ah' ties  or  characteristics  that  persist  through  all  accidental 
uses  and  that  can  be  identified  as  permanent  are  to  be  preferred. 

(2)  TL.e  operative,  instrumental,  or  manipulative  arts,  including 
machines,  tools,   and  manufacturing  processes,  should  be  classified 
according  to  whether  a  single  operation  of  one  kind  applicable  to 
various  materials  to  be  used  for  various  purposes  is  carried  out  by 
the  claimed  means,   or  whether  plural  operations  are  performed, 
which,  combined,  produce  a  special  effect  or  special  product. 

Example:  An  instrument  performing  a  plurality  of  operations  peculiar  to  shoe- 
manufacture  would  be  classified  on  the  basis  of  shoemaking,  because  that  instrument 
would  be  incapable  of  other  use,  while  an  instrument  peculiarly  adapted  to  drive 
nails  would  be  classified  on  the  basis  of  nailing,  whether  for  nailing  shoe-heels  or  other 
objects,  and  a  hammer  would  be  classified  on  the  basis  of  its  function  as  an  impact 
tool  even  though  described  as  for  driving  nails,  and  even  into  shoe-heels. 

(3)  Structures  (passive  instruments)  will,  in  general,  be  classified 
on  the  basis  of  structure,  either  of  special  or  general  application,  the 
essential  functions  and  effects  of  static  structures  being  resistive  or 
the  maintaining  of  forces  in  equilibrium. 

Example:  A  structure  recognized  as  peculiar  to  barriers  of  the  kind  known  as 
fences  would  be  classified  in  the  special  class  of  Fences,  but  posts,  joints,  beams,  etc., 
recognized  as  having  use  in  general  building,  even  though  described  as  used  in  fences, 
would  be  classified  in  a  more  general  building  class,  such  as  Wooden  Buildings  or 
Metallic  Building  Structures. 

(4)  Compositions  of  matter  and  manufactured  or  formed  stock  or 
materials  will  be  classified  in  accordance  with  the  inherent  character 
of  the  substance  or  material  where  possible,  otherwise  according  to 
special  use. 

Example:  A  pure  chemical  is  expected  to  be  classified  on  the  basis  of  its  chemical 
structure  and  constituents,  even  though  useful  as  a  food,  medicine,  dyestuff,  explo- 
sive, etc.,  and  alloys  on  the  basis  of  metallic  composition,  even  though  used  for  bear- 
ings, coins,  tools,  etc.;  whereas  a  physical  composition  having  no  reason  for  existence 
except  to  function  as  a  cleansing  composition  or  a  paint  might  have  to  be  classified 
on  the  basis  of  its  function  as  a  detergent  or  a  coating  composition,  respectively.  Also 
a  bimetallic  layered  foil,  plate,  or  wire  would  be  expected  to  be  classified  as  metal 
stock  even  though  designed  for  use  for  dental  filler,  plowshare,  or  electric  conductor, 
and  a  woven  textile  fabric  as  a  fabric  even  though  described  as  used  for  a  filter  or 
apron  for  a  paper-making  machine. 


CLASSIFICATION   OF   PATENTS.  27 

DIVISION    AND    ARRANGEMENT. 

(5)  The  divisions  or  subclasses  of  a  class  should  be  made  exhaus- 
tive, i.  e.,  they  should  be  susceptible  of  receiving  any  future  inven- 
tion that   may  fall  within   the  scope   of   the   class.     The   rule   as 
usually  phrased  is:  "The  constituent  species  must  be  equal,  when 
added  together,  to  the  genus."     Exhaustive  division  may  be  secured 
by  maintaining  always  a  residual  or  miscellaneous  subclass.     The 
miscellaneous  subclass  represents  the  remainder  of  the  original  un- 
divided material  undefined  except  as  the  class  is  defined  and  may  be 
accurately  treated  as  if  it  had  the  class  title. 

(6)  A  second  rule  respecting  the  subdivision  of  a  class  is:  "The 
constituent  species  must  exclude  each  other."     That  is,  the  divisions 
or  subclasses  must  not  overlap.     (See  exception  in  Rule  8.) 

Example:  If  a  number  of  balls  of  several  different  materials,  several  different  con- 
formations, or  constructions,  several  different  colors,  were  to  be  divided  into  glass  balls, 
hollow  balls,  and  red  balls,  this  rule  would  be  violated,  because  some  balls  would  be 
glass,  hollow,  and  red. 

(7)  AJthird  rule  respecting  subdivision  is:  "The  divisions  must  be 
founded  on  one  principle  or  basis."     The  application  of  this  rule  will 
generally  form  divisions   that  do  not  overlap.     (See  exception  in 
Rule  8.) 

Example:  If  a  number  of  balls  of  several  different  constructions,  several  different 
materials,  and  several  different  colors  were  to  be  classified  so  as  to  provide  a  place  for 
each  kind  of  characteristic,  they  should  be  divided  first,  for  example,  according  to  con- 
struction into  hollow  balls  and  solid  balls,  each  of  these  according  to  materials  into 
glass  balls,  rubber  balls,  metal  balls,  wooden  balls,  etc.,  and  each  of  the  latter  into  red 
balls,  blue  balls,  green  balls,  etc. 

(8)  When  it  is  found  that  division  into  overlapping  subclasses  and 
onfdifferent  characteristics  is  a  lesser  evil  than  an  unwieldy  number 
of  subclasses  that  would  otherwise  result,  then  those  subclasses  based 
on  characteristics  deemed  more  important  for  purposes  of  search 
should  precede  in  the  list  of  subclasses  those  based  upon  character- 
istics deemed  less  important.      (See  Rule  6.) 

(9)  In  arrangement  of  subclasses  or  subdivisions  the  miscellaneous 
groups  containing  material  not  falling  within  any  of  the  specifically 
entitled  subclasses,  should  stand  first;  those  subclasses  defined  by 
effect  or  special  use  should  precede  those  defined  by  function  or 
general  use;  those  containing  matter  that  is  related  to  the  matter  of 
other  subclasses  as  whole  to  part  should  precede  those  subclasses 
that  contain  the  part;  and  those  defined  by  a  characteristic  deemed 
more  important  or  significant  for  search  purposes  should  precede 
those  defined  by  characteristics  deemed  less  important. 

Whenever  superior  rank  has  leen  assigned  to  any  selected  character- 
istic by  placing  divisions  based  upon  it  in  advance  of  divisions  based 


28 


CLASSIFICATION    OF   PATENTS. 


upon   other   characteristics,    this  superiority   should   be  maintained 
throughout. 

Example:  A  partial  schedule  of  Class  80  follows  to  illustrate  the  arrangement  of 
subclasses: 


Class  80.— METAL  ROLLING. 


1.  Miscellaneous. 

2.  Heating  and  rolling. 

3.  Cutting  and  rolling. 

4.  Drawing  and  rolling. 

5.  Annular  bodies. 

6.  Screw  threads — 

7.  Concave  and  roll. 

8.  Platen  rolling — 

9.  Dies. 

10.  Rods  and  wires. 

11.  Tubes— 

12.  Idle  rolls. 

13.  Axial  rolling. 

14.  Segmental  rolls. 

15.  Skelping. 

16.  Wheels  and  disks. 

17.  Reworking. 

18.  Concave  and  roll. 

19.  Platen  and  roll. 

20.  Platen  rolling— 

21.  Disk  platens. 

22.  Axial  rolling — 

23.  Pattern  rolls. 


24.  Die  rolling— 

25.  Oscillating  rolls. 


Mills— 

32.  Coiling. 

33.  Work  reversing. 

Three  or  more  coacting  rollf 
Continuous — 
Inclined  trains. 


34. 
35. 
36. 


41.  Roll  cooling  and  heating. 

42.  Cooling  beds. 

43.  Feeding— 

44.  Tables. 


55.  Housings. 

56.  Roll  adjustments — 

57.  Relief  devices. 

58.  Rolls— 

60.  Processes — 
66.      Flanged  bars. 


In  this  schedule  the  miscellaneous  subclass  is  numbered  1,  then  follow  three  sub- 
classes (2-4)  of  rolling  plus  another  function,  then  four  major  subclasses  (5-16)  of 
rolling,  merely,  but  applied  to  blanks  of  special  form  producing  special  products, 
then  one  special  subclass  (17)  based  upon  a  special  class  of  material  treated,  then  five 
subclasses  (18-31)  specialized  in  type  and  mode  of  operation,  then  general  types  of 
rolling  mills  (32-40),  then  various  parts  and  accessories  (41-59),  then  processes  (60-66). 
This  is  the  usual  arrangement  and  is  an  exhaustive  division  for  the  art  of  metal  rolling. 
Had  there  been  miscellaneous  subclasses  for  all  combined  operations  of  rolling  plus 
some  other  function,  a  miscellaneous  subclass  for  all  mere  rolling  machines,  either 
special  or  general,  and  a  miscellaneous  subclass  for  all  parts  and  accessories,  the 
requirements  of  exhaustive  division  would  have  been  also  satisfied. 

In  the  illustrative  schedule,  there  being  no  miscellaneous  subclass  for  means  having 
combined  functions  of  rolling  and  another,  any  patent  having  claims  for  the  combi- 
nation of  a  means  for  rolling  and  a  means  for  cooling  would  fall  in  subclass  1,  Miscel- 
laneous. In  that  subclass  would  also  fall  all ' '  Mills, ' '  such  as  for  rolling  spiral  conveyer- 
flights,  the  same  not  falling  under  any  of  the  subclasses  32-40,  no  miscellaneous  sub- 
class of  "Mills"  and  no  special  article-rolling  subclass  having  been  provided;  also 
all  parts  or  accessories,  such  as  a  water-cooled  screen,  peculiarly  adapted  to  rolling- 
mills,  there  being  no  existing  subclass  of  screens  therein  and  no  miscellaneous  subclass 
of  parts.  The  arrangement  of  subclasses  in  Class  80  requires  that  the  combination 
of  a  furnace  and  a  rolling-mill  shall  be  placed  in  subclass  2,  even  if  the  combination 
be  designed  and  adapted  for  rolling  annular  bodies  (subclass  5)  or  tubes  (subclass  11). 
Means  special  to  rolling  a  tube  between  a  concave  and  roll  must  be  placed  in  subclass 


CLASSIFICATION    OF   PATENTS.  29 

13  rather  than  in  subclass  18.     A  work-reversing  mill  must  be  placed  in  subclass  33 
rather  than  in  subclass  34  even  though  it  have  three  or  more  coacting  rolls. 

The  rolling  of  "Screw-threads"  having  been  given  higher  rank  than  a  "Concave 
and  roll"  mechanism,  any  concave  and  roll  mechanism  limited  for  use  in  rolling 
screw-threads  should  be  formed  into  a  subclass  indented  under  "Screw-threads" 
and  not  into  a  subclass  "Screw-threads  "  indented  under  "  Concave  and  roll." 

(10)  Class  schedules  are  arranged  with  certain  subclasses  appro- 
priately indented  according  to  a  commonly  understood  expedient. 
In  a  properly  indented  schedule  subclasses  in  column  at  the  extreme 
left  are  the  main  species  (the  proximate  species)  of  the  class.     The 
titles  and  definitions  of  all  subclasses  proximate  to  the  class   (at 
extreme  left)  must  be  read  with  the  title  and  definition  of  the  class, 
as  if  indented  under  the  class  title  one  space  to  the  right;  so  also 
with  the  titles  and  definitions  of  subclasses  indented  under  other 
subclasses.     If  a  title  has  no  number  (as  in  Class  80,  "Mills  "),  it  repre- 
sents merely  a  subject-matter  to  be  divided,  assumed  to  have  no 
representatives  other  than  those  in  the  species  indented  under  it. 
If  a  title  having  indented  species  under  it  has  a  number,  it  not  only 
represents  a  subject  to  be  divided  but  also  a  subclass  including  all 
other  species  not  falling  within  the  indented  titles.     Indention  does 
not  indicate  superiority  or  inferiority,  but  merely  that  the  title  and 
the  definition  of  the  indented  subclass  must  be  read  with  the  title 
and  definition  of  the  subclass  under  which  it  is  indented.     A  title 
selected  in  a  scheme  of  subdivision  to  be  of  first  importance  and 
placed,  therefore,  in  advance,  should  not  thereafter  be  indented  under 
a  title  selected  to  be  of  secondary  importance  and,  therefore,  having 
a  lower  position.     (See  Rule  8.) 

(11)  A  group  of  material  may  be  divided  on  several  different  bases- 
"Use"  or  " purpose"  or  " object  treated"  may  be  adopted  only 
when  the  "use"  or  " purpose"  or  " object  treated"  stamps  upon  the 
invention  such  peculiarities  of  operation  or  construction  as  to  limit 
the  applicability  of  the  invention  to  the  use  or  purpose  named. 
(See  Basis  of  Classification,  Rule  1.)     A  group  based  upon  mode  of 
operation  also  may  be  divided  into  subclasses  (1)  with  a  " functional" 
title,  usually  participial  in  form,  and  adapted  therefore  to  receive 
machines,  processes,   and  tools;     (2)   with  special  use,  purpose,  or 
object-treated   title  containing   the  name  of    the  use,  purpose,  or 
object;   (3)  with  "  type  "  title,  usually  a  name  or  a  name  with  a  qualify- 
ing adjective;    (4)  with  a  title  of  a  part  or  subcombination,  also  a 
name. 

Example:  In  Class  90,  Gear-Cutting,  Milling,  and  Planing,  are  to  be  found  sub- 
classes entitled  "Gear-cutting,"  certain  machines  being  peculiar  to  that  use;  also 
other  subclasses  with  the  general  functional  title  "Planing,"  subordinate  to  which 
are  the  special  use  subclass  "Planing,  Soft  metal,"  and  the  type  subclass  "Planers" 
divided  into  two  coordinate  subclasses,  "Reciprocating  bed"  and  "Reciprocating 
cutter,"  and  several  subordinate  "part"  subclasses,  including  "Tool-feeds"  and 


30  CLASSIFICATION    OF   PATENTS. 

"Tool-heads."  The  adjective  form  of  the  title  "Planers,  Reciprocating  bed,"  indi- 
cates a  type  subclass.  If  the  title  had  been  Planers,  Reciprocating  beds,  the  indica- 
tion would  be  that  the  subclass  was  a  part  subclass  to  receive  planer  beds  only.  In 
the  class  referred  to  for  illustration,  "Tool-feeds"  and  "Tool-heads"  indicate  sub- 
classes for  parts  and  not  for  types  of  planers  having  tool  feeds. 

(12)  In  arranging  the  divisions  of  a  class,  such  arrangement  should 
be  sought  as  will  minimize  the  need  of  cross-references.  Search  for 
any  particular  matter  can  not  always  be  limited  to  one  group  without 
such  extensive  cross-referencing  as  would  in  some  cases  defeat  the 
purpose  of  classification.  Forming  the  subdivisions  of  a  class  accord- 
ing to  the  total  similarities  of  the  inventions,  rather  than  according 
to  some  selected  more  or  less  important  characteristic,  and  arranging 
them  in  the  correct  order  of  superiority  and  inferiority,  with  care  to 
maintain  throughout  the  schedule  the  relative  positional  values  of 
the  several  selected  bases  of  division,  will  ordinarily  in  a  closely 
bonded  class  limit  the  search  for  any  single  invention  to  the  subclass 
particularly  suited  to  receive  it  and  some  subclasses  preceding  that 
one,  excluding  from  the  ncessity  of  search  the  subclasses  succeeding. 

Example:  In  Class  80,  Metal-Rolling,  it  would  not  be  expected  to  find  any  tube- 
rolling  mill  lower  in  the  schedule  than  the  tube-rolling  subclasses,  but  a  tube-mill 
might  be  found  higher  up  in  "Heating  and  rolling,"  "Drawing  and  rolling,"  etc. 
No  concave  and  roll  combination  should  be  found  succeeding  the  subclass  of  "Concave 
and  roll,"  but  it  may  be  found  under  subclasses  above,  such  as  "Tubes,  Screw- 
threads,"  etc.  No  rolls  should  be  found  lower  than  the  subclass  of  "Rolls,"  but 
they  may  be  found  in  many  subclasses  above. 

DEFINITION. 

( 13)  Having  some  knowledge  of  the  nature  of  the  materials  about 
to  be  classified,  a  tentative  definition  of  a  class  to  be  formed  may  be 
framed,  which  may  be  either  written  down  or  merely  carried  in 
mind,    to   serve   as    a   tentative   guide.     This    tentative   definition 
must  be  considered  as  subject  to  change  to  any  extent  by  the  fuller 
knowledge  obtained  by  careful  consideration  of  the  material.     After 
a  full  knowledge  of  the  materials  to  be  classified  has  been  acquired, 
it  will  be  necessary  to  frame  a  careful  definition  of  the  class,  and 
also  of  each  subclass  whose  title  does  not  unequivocally  indicate 
what  is  contained  in  it. 

(14)  A  definition  of  any  class  should  state  the  "  qualities  and 
circumstances  possessed  by  all  the  objects  that  are  intended  to  be 
included  in  the  class  and  not  possessed  completely  by  any  other 
objects."     A  proper  definition   should  not  ordinarily  contain  the 
name  of  the  thing  defined.     " Definitions  in  a  circle"  are,  of  course, 
worthless.     A  definition  should  be  exactly  equivalent  to  the  species 
defined  and  should  not  be  expressed  in  obscure  or  ambiguous  language, 
but  should  employ  terms  already  defined  or  perfectly  understood. 
It  should  not  be  in  negative  form  where  it  can  be  affirmative.     If 


CLASSIFICATION    OF    PATENTS.  31 

the  class  of  objects  has  a  peculiar  property,  the  naming  of  that  may 
serve  as  a  definition.  If  no  peculiar  property  can  be  detected,  the 
definition  should  name  more  than  one  quality  or  property.  Several 
different  classes  may  have  one  or  more  properties  alike,  but  as  the 
number  is  increased  the  likelihood  of  there  being  others  having  the 
same  properties  is  decreased.  The  briefest  possible  statement  of 
such  properties  or  qualities  as  are  possessed  by  all  the  objects  of  a 
class  and  not  completely  possessed  by  any  other  objects,  which  will 
suffice  to  distinguish  the  class  from  other  classes  and  determine  its 
position  in  the  general  classification,  will  be  most  satisfactory.  To 
define  any  species,  the  genus  having  been  defined,  the  genus  should 
be  named  and  the  difference  added.  Of  course,  no  generic  definition 
should  contain  any  limitation  not  characteristic  of  every  species 
of  the  defined  genus.  In  seeking  qualities  by  which  to  describe  a 
genus  or  species,  no  accident  should  be  selected. 

Example:  Suppose  there  be  marked  out  and  defined  as  a  genus  all  means  whereby 
one  form  of  energy  is  transformed  into  another  form  of  energy  and  no  more,  and  the 
genus  be  named  energy-transformers.  We  may  then  name,  as  species,  energy-trans- 
formers that  are  motors  and  energy-transformers  that  are  not  motors.  Motors  may  be 
denned  by  merely  naming  the  genus  energy-transformers,  and  stating  the  difference, 
to  wit,  continuously  transforming  energy  into  cyclical  mechanical  motion.  Then  the 
definition  will  be:  Energy-tranpformers  that  are  adapted  to  continuously  transform 
energy  into  cyclical  mechanical  motion.  The  non-motor  division  will  retain  the  genus 
definition. 

It  would  not  be  illuminating  for  a  searcher  having  little  familiarity  with  the  textile 
arts  to  look  under  the  title  "Carding"  and  find  that  carding  is  defined  as  a  means  for 
carding  fiber. 

Even  though  the  first  steam-engine  invented  had  been  used  to  run  a  gristmill,  the 
accident  of  its  use  as  a  part  of  a  gristmill  would  hardly  warrant  the  definition  of  a 
steam-engine  as  a  means  to  grind  corn.  Nor  would  a  hammer  be  properly  defined  as 
an  instrument  to  drive  nails  or  to  crack  nuts  or  to  forge  horseshoes,  even  though  a 
patent  should  not  mention  any  use  other  than  one  of  these  and  should  lay  heavy 
emphasis  on  the  special  value  of  the  hammer  as  a  nut  cracker,  nail  driver,  etc. 

(15)  In  those  cases  where  the  title  is  so  obvious  that  definition  is 
superfluous,  explanatory  notes  may  be  substituted  and  will  usually 
be  found  helpful. 

CROSS-REFERENCES    AND    SEARCH-NOTES. 

(16)  Inasmuch  as  nearly  every  patent  discloses  unclaimed  matter 
that  is  classifiable  separately  from  the  claimed  matter,  it  is  clearly 
impossible  to  cross-reference  every  disclosure  of  every  means  in  every 
patent.     Many  things  must  be  taken  as  conventional,  obvious,  or 
well  known,  and  the  good  judgment  of  the  classifier  is  bound  to  be 
exercised  in  cross-referencing  matter  disclosed  but  not  claimed  to  be 
the  invention  of  the  patentee. 

(17)  A  mere  part  or  element   should   rarely  be  cross-referenced 
from  an  element  class  to  a  superior  combination  class.     An  element 


32  CLASSIFICATION    OF   PATENTS. 

forming  part  of  a  combination  in  a  superior  class  should,  if  claimed, 
be  cross-referenced  to  the  element  class  and  also  if  not  claimed  if  it 
seems  to  be  not  merely  a  conventional  form,  and  patents  having 
claims  for  more  than  one  differently  classifiable  invention  should 
always  be  cross-referenced  unless  such  an  arrangement  of  subclasses 
with  search-notes  is  substituted  as  will  guide  the  searcher  to  all 
places  where  the  material  may  be  found.  Claimed  matter  additional 
to  that  which  controls  the  classification,  if  belonging  in  the  same  class, 
should  be  cross-referenced  into  a  succeeding  subclass.  Cross-refer- 
ences of  unclaimed  disclosure  may  be  in  either  direction. 

(18)  To  supplement  or  take  the  place  of  cross-referencing,  more  or 
less  elaborate  search-notes  are  needed,  giving  directions  and  sugges- 
tions for  further  search,  setting  out  the  relationship  between  classes 
and    subclasses,    and    drawing    distinctions    by    example.     Search- 
notes  should  indicate  other  classes  or  subclasses  in  which  the  subject- 
matter  of  the  group  to  which  the  search-notes  are  appended  is  likely 
to  form  a  part  of  a  more  intensive  combination,  also  analogous  mat- 
ter that  might  serve  as  a  reference  for  a  broad  claim.     They  need  not, 
in  general,  indicate  where  parts  or  elements  of  the  subject-matter 
which  are  common  also  to  other  classes  can  be  found,  because  the 
index  of  classes  contains  the  necessary  information.     For  example,  it 
is  not  necessary  in  every  machine-class  to  indicate  by  search-notes 
where  machine-elements  and  static  parts  may  be  found,  nor  in  a  class 
of  wooden  boxes  to  point  out  where  the  nails,  screws,  hinges,  or 
locks  that  may  form  a  part  of  the  box  are  classified. 

DIAGNOSIS    TO   DETERMINE    CLASSIFICATION. 

(19)  Inasmuch  as  nearly  every  patent  contains  disclosure  that  is 
claimed  and  also  disclosure  that  is  not  claimed,  it  has  been  deemed 
advisable  to  establish  the  general  rule  that  where  the  claimed  and 
unclaimed  disclosures  are  classified  in  different  classes  or  subclasses 
the  invention  both  disclosed  and  claimed  shall  determine  the  placing 
of  a  patent  (or  a  pending  application)  rather  than  any  selected  in- 
vention that  may  be  disclosed  but  not  claimed .    1 1  Not  claimed ' ;  covers 
means  that  may  form  an  element  only  of  a  claim  as  well  as  means  not 
referred  to  in  any  claim.     (See  exceptions  in  Rules  21  to  22  inclusive.) 

Example:  A  patent  discloses  and  claims  a  dash-pot  but  illustrates  it  in  such  relation 
to  a  metal-planing  machine  as  to  utilize  it  for  checking  the  movement  of  the  bed  at 
one  end  of  its  path,  or  in  connection  with  an  electric  generator  to  aid  in  effecting  the 
brush  adjustment;  the  patent  should  be  classified  in  the  subclass  of  Dash-pots.  If 
the  classifier  finds  the  disclosed  organization  of  dash-pot  and  planer  or  dash-pot  and 
generator  more  than  a  conventional  illustration  of  an  obvious  use,  he  should  note  a 
cross-reference  to  Planers  or  Electricity,  Generation.  A  patent  discloses  an  internal- 
combustion  engine  associated  with  a  specific  form  of  carbureter;  the  claims  relate 
to  the  engine  parts  only;  the  class  of  Internal-Combustion  Engines  should  receive 
the  patent,  and  a  cross-reference  should  be  placed  in  Carbureters.  A  patent  discloses 
and  specifically  claims  the  combination  of  a  rail-joint  comprising  abutting  rails,  fish- 


CLASSIFICATION"    OF   PATENTS.  33 

plates,  and  specific  bolts;  the  patent  goes  to  an  appropriate  class  of  rail-joints,  and 
if  the  bolt  is  more  than  a  mere  obvious  conventional  bolt,  a  cross-reference  should  be 
noted  for  the  appropriate  subclass  of  Bolts. 

(20)  The  totality  of  the  claimed  invention  should  be  selected  when 
possible  to  determine  the  appropriate  class  in  which  to  place  a  patent. 
The  entire  expression  of  the  invention  will  usually  be  set  forth  in  the 
most  relatively  intensive  claim.1     In  a  properly  drawn  patent  there 
is  at  least  one  claim  that  will  serve  as  a  mark  to  indicate  the  classi- 
fication of  that  patent. 

(21)  Where  a  patent  discloses  but  does  not  claim  a  combination 
of  proper  scope  to  be  classified  in  a  combination  subclass  and  claims 
merely  a  detail  classified  in  a  subclass  lower  in  the  schedule,  both  in 
the  same  class,  if  the  subclasses  are  so  related  that  the  combination 
always  involves  the  detail  so  that  a  search  for  the  detail  must  neces- 
sarily be  made  in  the  combination  subclass,  the  patent  may  be  placed 
in  the  combination  subclass.     This  avoids  the  need  of  a  cross  refer- 
ence into  the  combination  subclass,  and  a  lack  of  a  copy  in  the  detail 
subclass  is  immaterial,  as  it  is  seen  in  the  completion  of  the  search 
through  the  combination  subclass.     (See  Rule  19.) 

Example:  A  patent  for  a  saw-making  machine  discloses  dressing,  jointing,  and 
gaging  mechanisms;  it  claims  dressing  and  jointing  only.  There  is  a  subclass  for 
dressing,  jointing,  and  gaging,  and  a  subclass  for  dressing  and  jointing.  In  this  case 
the  patent  may  be  placed  in  the  first-mentioned  subclass,  as  that  must  be  searched 
always  when  the  second-mentioned  one  is  searched,  cross  referencing  in  this  situation 
being  of  little  value. 

(22)  Where  a  subclass  with  a  generic  title  has  indented  thereunder 
a  species   type-subclass  bearing   the   title   of   the  generic   subclass 
qualified  by  a  difference,  any  patent  which  claims  an  invention  fall- 
ing within  the  genus  subclass  and  discloses  the  qualification  of  the 
species  type-subclass  should  be  classified  in  the  latter  whether  or  not 
the  entire  disclosure  is  claimed.     (See  Rule  19.) 

Example: 

Class  29.— METAL  WORKING. 
Machine  chucks  and  tool  sockets — 
Cam  closing — 

126.  Scroll— 

127.  Bevel  pinion  or  ring. 

1  All  terms  have  a  meaning  in  extension  and  in  intension.  The  meaning  of  a  term  in  extension  consists 
of  the  objects  to  which  the  term  may  be  applied;  its  meaning  in  intension  consists  of  the  qualities  neces- 
sarily possessed  by  objects  bearing  that  name.  The  term  "motors"  in  extension  means  all  motors- 
electric,  gas,  water,  spring,  weight,  etc.  "Motors"  in  intension  means  instruments  to  convert  some  form 
or  manifestation  of  energy  into  periodical  or  cyclical  motion  of  a  body.  As  the  intension  increases  the  exten- 
sion decreases,  and  vice  versa.  There  must  be  more  motors  than  there  are  electric  motors,  and  electric 
motors  have  more  qualifications  than  are  common  to  all  motors.  Comparison  of  arts  and  instruments  with 
respect  to  their  extension  and  intension  for  classification  purposes  should  be  made  between  comparable 
qualities  A  claim  for  a  steam-engine  may  be  very  specific  while  a  claim  for  a  reaper  may  be  very  broad; 
here  there  is  no  comparable  relationship,  and  the  terms  intensive  and  extensive  do  not  have  the  relative 
significance  most  useful  in  classification.  But  when  a  patent  or  application  contains  claims  for  mechanism 
peculiar  to  electric  motors  and  other  claims  for  mechanism  common  to  electric  motors  and  other  kinds  of 
motors,  the  claims  for  the  electric  motor  would  control  the  classification. 


34  CLASSIFICATION    OF   PATENTS. 

If  a  patent  claimed  only  the  scroll  of  a  scroll-chuck,  but  disclosed  it  in  connection 
with  a  bevel  pinion  and  ring,  it  should  be  classified  in  subclass  127,  Bevel  pinion  and 
ring,  and  not  in  subclass  126,  Scroll,  although  if  there  were  no  disclosure  of  the  bevel 
pinion  and  ring  it  would  go  in  subclass  126.  Any  search  for  scrolls  must  be  prosecuted 
through  all  subclasees  that  include  "Scroll"  in  the  title. 

(23)  Where,  as  in  the  case  of  patents  that  show  and  claim  a  combi- 
nation that  as  matter  of  common  knowledge  is  not  new  except  in  one 
of  its  elements,  to  classify  a  patent  strictly  in  accordance  with  rule 
would  result  in  placing  the  patent  where  it  would  serve  no  useful  pur- 
pose as  a  reference  and  having  to  cross-reference  it  to  a  class  where 
it  would  serve  a  useful  purpose,  it  is  best  to  classify  the  patent  in 
the  class  to  which  the  element  would  take  it.     (See  Rule  19.) 

Example:  A  patent  claiming  a  wheeled  vehicle,  broadly,  in  combination  with  an 
internal-combustion  engine  comprising  a  cylinder,  a  crank-case,  a  piston  and  suitably- 
<K)nnected  crank,  a  valve  opening  into  the  crank-case,  and  a  valve  in  the  piston  open- 
ing into  the  cylinder,  may  be  advantageously  classified  as  an  internal-combustion 
engine  notwithstanding  the  alleged  invention  is  for  a  motor  vehicle. 

(24)  In  order  to  meet  the  situation  respecting  the  classification 
of  those  patents  that  indiscriminately  claim  an  article  of  manufacture 
defined  only  by  the  material  of  which  it  is  made  and  those  patents 
that  claim  those  materials,  leaving  to  the  specification  information 
regarding  the  designed  uses,  patents  for  articles  defined  only  by  their 
ingredients  specifically  set  forth  may  be  placed  in  the  composition 
of  matter  or  material  class.     (See  Rule  19.) 

Example:  A  patent  having  a  claim  for  a  cutter  made  of  an  alloy  of  iron,  tungsten, 
and  manganese  would  be  classified  with  Alloys;  a  patent  claiming  a  box  made  of 
paper  composed  of  two  layers  united  by  a  solution  of  asphaltum  should  go  to  the  class 
of  Laminated  Fabric  and  Analogous  Manufactures,  rather  than  to  paper  boxes;  and 
a  patent  for  a  house  having  its  exterior  coated  with  equal  quantities  by  volume  of 
carbonate  of  lead  and  oxid  of  barium  suspended  in  a  vehicle  of  linseed-oil  would  be 
classified  as  a  paint  rather  than  as  a  house. 

(25)  An  alleged  process  of  utilizing  a  specifically-defined  compo- 
sition or  material  which  consists  in  merely  applying  it  to  the  use  it 
was  designed  for  may  be  classified  as  a  composition  or  material 
rather  than  as  a  process.     (See  Rule  19.) 

Example:  A  process  of  painting  the  bottom  of  a  marine  vessel  which  consists  in 
applying  thereto  a  composition  consisting  of  sulphate  of  copper,  powdered  metallic 
zinc,  chlorid  of  antimony,  and  hyposulphite  of  soda,  in  a  vehicle  of  linseed  oil, 
would  be  more  usefully  classified  as  an  antifouling  paint  than  as  a  ship,  as  the  inven- 
tion would  hardly  be  distinguishable  from  a  paint  claimed  as  such  and  described  for 
use  on  submarine  surfaces. 

(26)  An  alleged  process  consisting  merely  in  the  use  of  a  particu- 
larly-defined machine  or  similar  instrument  operating  according  to 
its  law  of  action  will  ordinarily  be  classified  in  the  class  or  subclass 


CLASSIFICATION   OF  PATENTS.  35 

where  the  machine  belongs.  But  if  in  addition  to  defining  the  opera- 
tion of  a  particular  machine  the  claim  also  specifies  acts  not  per- 
formed by  the  machine,  the  classification  should  be  in  the  class  or 
subclass  in  which  the  process  belongs.  (See  Rule  19.) 

Example:  Thus  a  claim  for  a  method  of  rolling  an  iron  plate  which  consists  in  pass- 
ing an  iron  blank  between  a  pair  of  rolls  arranged  horizontally  in  juxtaposition  one 
above  the  other  and  geared  together  so  as  to  rotate  in  opposite  directions,  and  causing 
an  idle  roll  supported  in  bearings  on  the  roll-housings  to  bear  against  the  central 
portion  of  the  surface  of  one  of  the  first  pair  of  rolls  on  the  upper  side  thereof,  should 
be  classified  as  a  rolling-mill,  while  if  to  that  claim  were  added  the  steps  of  doubling 
the  sheet  after  one  passage  between  the  rolls,  again  passing  between  the  rolls,  again 
doubling,  and  then  passing  the  now  four-ply  pack  between  the  rolls  sidewise  or  turned 
90  per  cent  to  the  direction  in  which  it  had  previously  been  fed,  the  classification 
should  be  with  processes  of  sheet-metal  manufacture. 

(27)  In  the  absence  of  settled  rules  defining  permissible  joinder  of 
inventions,  there  may  be  in  one  patent  claims  for  one  or  more  or  all 
of  the  classes  of  invention  named  in  the  statute,  to  wit,  machine,  art, 
manufacture,  and  composition  of  matter.     There  may  also  be  claims 
to  several  more  or  less  related  inventions  in  the  same  statutory  class 
of  invention  but  each  belonging  to  a  different  industrial  art.   (1) 
Where  different  main  classes  are  involved,  the  patent  will  be  classi- 
fied by  the  most  intensive  invention,  without  regard  to  the  statutory 
class  to  which  it  belongs.     (2)  Where  different  subclasses  of  the  same 
class  are  involved,  the  patent  will  be  classified  in  that  one  of  the  sev- 
eral subclasses  defined  to  receive  the  several  inventions  which  stands 
highest  in  the  schedule  of  subclasses. 

(28)  Where  a  patent  contains  claims  for  all  or  a  plurality  less  than 
all  of  the  statutory  classes,  the  general  rule  of  preference  or  superi- 
ority of  the  several  classes  or  subclasses  is  that  represented  by  the 
following  order,  to  wit:  (1)  Machine  (or  other  operative  instrument) ; 
(2)  Art;  (3)  Manufacture;  (4)  Composition  of  matter.     This  order 
is,  in  a  general  way,  the  order  of  intensiveness  of  the  several  kinds  of 
invention.     (See  Rules  29-35.) 

Example:  An  automatic  screw-machine,  peculiarly  adapted  to  carry  out  a  process 
of  making  a  novel  form  of  machine-screw  out  of  a  new  iron  alloy,  and  having  a  claim 
to  the  machine,  to  the  process,  to  the  screw,  and  to  the  alloy,  would  be  assigned  to 
Metal-Working,  Combined  machines,  and,  if  all  claims  were  allowed,  cross-referenced 
to  Bolt  and  rivet-making  processes,  to  Bolts,  and  to  Alloys.  If  the  claim  to  any  one 
or  two  of  the  subjects  were  eliminated,  the  order  of  preference  or  superiority  and  the 
order  of  cross-referencing  would  remain  the  same. 

(29)  Patents  containing  a  plurality  of  claims  for  several  different 
statutory  kinds  of  invention  that  are  classifiable  in  different  main 
classes,  and  wherein  the  rule  of  relative  intensiveness  varies  from  the 
order  Machine,  Art,  Manufacture,  and  Composition  of  matter,  may 
be  diagnosed  and  classified  as  directed  in  the  following  paragraphs 
(30  to  35). 


36  CLASSIFICATION    OF   PATENTS. 

(30)  Where  a  patent  contains  claims  for  a  process  and  for  an  appa- 
ratus susceptible  of  use  as  an  instrument  in  carrying  out  the  process, 
but  not  peculiar  to  that  use,  or  for  an  apparatus  adapted  to  carry  out 
but  one  step  or  only  a  part  of  the  process,  the  process  claim,  being  in 
this  instance  the  more  intensive,  would  control  the  classification- 
(See  rule  28.) 

Example:  In  a  patent  containing  a  claim  for  a  process  of  roasting  ore  and  then  col- 
lecting the  fumes,  and  another  claim  for  a  roasting  furnace  that  is  a  mere  material-heat- 
ing furnace,  the  process  claim  would  control;  whereas,  if  one  claim  were  for  a  method 
of  roasting  ores  consisting  of  stirring  the  ore,  applying  heat  to  the  same,  and  collecting 
the  solids  from  the  fumes,  and  the  other  claim  were  for  a  heating  furnace  having  a 
etirrer  and  a  fume  arrester,  the  apparatus  claim  would  control.  And  if  a  patent  con- 
tained claims  for  a  process  of  roasting  ores,  and  other  claims  for  a  furnace  susceptible 
of  use  in  carrying  out  the  process  but  equally  useful  in  annealing  glass  or  steel  articles, 
the  process  claim  would  control. 

(31)  Where  a  patent  claims  a  specified  article  of  manufacture  or 
other  product,  and  also  an  instrument  for  making  a  part  only  of  that 
specified  article  or  other  product,  the  product  claim,  being  more 
intensive,  should  control  the  classification;  so  also  in  case  of  a  claim 
for  a  product  and  a  claim  for  an  instrument  performing  any  minor 
act  with  respect  thereto.     (See  Rule  28.) 

Example:  Where  a  patent  claims  a  particular  construction  of  a  riveted  joint,  and 
also  a  tool  for  calking  the  rivet,  and  where  a  patent  claims  a  particular  construction  of 
shoe,  and  also  a  buttonhook  for  buttoning  said  shoe,  the  article  and  not  the  tool  claims 
•control. 

(32)  Where  a  patent  contains  claims  to  a  process  and  a  product, 
the  process  claims  govern  the  classification  in  those  cases  where  search 
among  machines  for  making  the  product  would  have  to  be  made,  and 
such  processes  would  be  classifiable  on  the  basis  of  the  mode  of  opera- 
tion, usually  in  the  same  class  with  machines  for  practicing  such 
processes.     (See  Rule  28.) 

Example:  A  patent  having  a  claim  for  a  process  of  making  bifocal  lenses,  consisting 
in  grinding  the  surface  of  one  piece  of  glass  to  form  a  convex  lens,  heating  another  piece 
of  glass  until  it  is  plastic,  then  forcing  the  ground  surface  of  the  first-named  piece  into 
the  body  of  the  latter  and  gradually  cooling  the  lens-blank  thus  formed;  and  also  a 
claim  for  a  bifocal  lens  composed  of  two  pieces  of  glass  weld-united,  would  be  classi- 
fied in  Glass-manufacture  and  cross-referenced  into  lenses.  Or  a  patent  having  a  claim 
to  a  process  of  making  a  metal  plate  with  elongated  perforations,  consisting  in  forming 
round  perforations  in  the  plate  and  subsequently  rolling  the  plate,  thereby  thinning 
and  elongating  the  plate  and  elongating  the  openings,  and  also  a  claim  to  a  metallic 
plate  having  relatively  long  and  narrow  perforations,  would  be  classified  on  the  basis 
of  the  process  claim. 

(33)  Where  a  patent  claims  both  process  and  product,  and  the 
alleged  process  is  disclosed  in  the  product,  so  that  search  would  have 
to  be  made  in  the  appropriate  class  of  products,  the  product  will  be 
adopted  as  the  basis  of  classification,  and  classification  will  be  in 
the  appropriate  product  class.     (See  Rule  28.) 


CLASSIFICATION    OF    PATENTS.  37 

Example:  A  claim  for  a  process  of  making  a  pencil  consisting  in  assembling  a  core 
of  graphite  with  a  sheathing  of  wood,  and  attaching  a  cap  of  rubber-composition  to 
one  end,  would  be  classified  as  a  pencil  rather  than  as  a  process,  because  conception 
of  the  article  is  inseparable  from  the  process  and  search  must  be  made  in  the  article 
class. 

(34)  Where  a  patent  claims  a  process  of  making  a  composition  of 
matter,  and  also  the  composition  of  matter,  the  claims  will  be  classi- 
fied in  general  in  accordance  with  the  classification  of  the  composi- 
tion of  matter  in  all  cases  where  the  process  is  peculiarly  adapted  to 
produce  the  composition,   as  by  setting  forth  the  introduction  or 
assemblage    of    particular    ingredients,    since    those    processes    that 
include   the   selection   of   particular   ingredients   necessitate   search 
among  compositions  having  such  ingredients.     (See  Rule  28.) 

Example:  A  patent  having  a  claim  for  a  composition  consisting  of  a  mixture  of 
caoutchouc  and  casein,  and  a  claim  for  the  process  of  preparing  a  rubberlike  sub- 
stance which  consists  in  adding  undissolved  raw  caoutchouc  to  casein  and  thoroughly 
mixing  and  kneading  the  mass,  would  be  classified  according  to  the  composition. 

(35)  Where  a  patent  claims  a  product  such  as  a  specific  article 
of  manufacture,  or  a  specific  composition  of  matter,  and  also  claims 
a  process  of  general  application  for  making  one  of  the  parts  of  the 
article  or  one  of  the  ingredients  of  the  composition,   the  product 
claim  should  control  the  classification.     (See  Rule  28.) 

Example:  If  a  patent  claimed  a  woven  textile  fabric  having  the  yarns  interlaced 
in  a  defined  relation,  and  a  process  of  spinning  a  yarn  utilized  in  the  fabric;  or  if  a 
patent  claimed  a  varnish  composed  of  shellac,  dissolved  in  wood  alcohol,  and  a  pig- 
ment, and  also  contained  a  claim  for  distilling  wood  to  obtain  the  alcohol,  the  product 
claim  would  control  the  classification  in  each  instance,  and  the  process  would  be 
cross-referenced. 

(D)  PROCEDURE   IN   RECLASSIFYING   WITHIN  EXAMINING 

DIVISIONS. 

(1)  Do  not  start  to  make  a  new  class  or  revise  an  old  one  with  pre- 
conceived fixed  notions  respecting  its  scope  and  the  particular  sub- 
divisions required.  Wait  until  all  patents  pertinent  to  the  subject 
have  been  seen  and  adequate  knowledge  of  them  acquired.  In  other 
words,  make  no  a  priori  classification  but  discover  and  assemble  all 
the  facts  and  from  them  make  your  inductions.  Then  the  common 
characteristics  of  the  subject-matter  of  the  class  may  be  intelligently 
defined,  the  limitations  of  the  class  marked  out,  and  its  relation  to 
other  classes  set  forth.  Bear  in  mind  that  the  Patent  Office  classi- 
fication deals  with  the  subject-matter  of  the  useful  arts  rather  than 
merely  with  existing  classes,  and  that  it  is  not  therefore  essential  to 
retain  classes  that  are  found  to  be  composed  of  unrelated  or  too 
distantlv  related  units. 


38  CLASSIFICATION    OF   PATENTS. 

Assuming  that  the  work  of  reclassification  is  undertaken  by  exam- 
iners who  are  already  experienced  in  the  subject-matter  to  be  classi- 
fied, procedure  as  follows  is  recommended : 

(2)  Utilizing  your  previously  acquired  knowledge  of  the  patents  in 
the  class  you  are  about  to  revise,  subdivide  the  existing  subclasses 
into  bundles,  so  as  to  assemble  in  each  bundle  those  patents  deemed 
to  have  the  closest  resemblance  to  each  other.     For  the  purpose  of 
this  assemblage,  consider  each  patent  as  an  entirety  and  not  with 
reference  to  various  more  or  less  important  parts  of  that  entirety. 

Example:  An  apparatus  comprising  in  alleged  combination  a  means  for  decanting 
water,  a  means  for  electrolytically  depositing  impurities,  and  a  means  for  filtering  the 
water,  should  not  be  classified  either  as  a  decanter,  an  electrolytic  apparatus,  or  a 
filter,  but  should  be  classified  as  a  combination  apparatus  (taking  it  to  the  general  art 
of  liquid  purification).  So  also  the  combination  of  a  rotary  printing-press  with  a 
folding  mechanism,  and  a  wrapping  mechanism,  should  not  be  classified  merely  as  a 
rotary  printing-press,  a  folding  machine,  or  a  wrapping  machine,  but  should  be 
classified  as  a  combination  of  the  several  mechanisms  as  an  entirety  whose  functions 
carried  out  in  proper  order  produce  a  printed  and  wrapped  newspaper. 

(3)  Write  an  approximate  or  tentative  definition  of  the  matter 
thus   assembled  in  each  bundle   and   attach  it   to   its   appropriate 
bundle. 

(4)  Where  it  appears  that  the  subject  matter  of  any  bundle  formed 
from  the  patents  of  any  subclass  is  analogous  to  matter  in  other  sub- 
classes of  the  same  class  or  in  other  classes,  a  note  should  be  added 
to  that  effect  so  that  this  matter  may  be  given  special  consideration. 

(5)  When  the  same  examiner  or  different  examiners  are  working 
on  different  subclasses  containing  analogous  matter,  parallel  lines  of 
subdivision  should  be  followed  wherever  possible,  in  order  to  effect 
an  arrangement  that  will  facilitate  comparisons. 

(6)  When  subdividing  a  group  of  more  or  less  complex  organized 
structures  or  mechanisms,  note  should  be  taken  of  subcombinations 
that  form  or  it  is  thought  should  form  the  basis  of  other  subclasses, 
either  in  the  same  or  different  classes,  into  which  those  details  may  be 
collected,  either  classified  therein  originally  or  by  cross-reference. 

Example:  Assuming  that  the  combination  of  press,  folder,  and  wrapping  mechan- 
ism, referred  to  in  a  preceding  paragraph  is  to  be  classified  in  a  class  of  Printing,  on 
the  entirety  as  a  combination  having  the  function  of  printing,  plus  other  functions, 
and  that  folding  and  also  wrapping  are  separately  classified,  then  the  particular  type 
of  press  should  be  selected  to  be  cross-referenced  into  a  press-type  subclass  of  the  class 
of  Printing,  such  as  "Presses,  rotary,"  while  the  folding  mechanism  and  the  wrapping 
mechanism  would  be  noted  for  cross-reference  to  other  appropriate  classes.  Also, 
any  part  of  the  printing  press,  such  as  the  inking  mechanism,  specifically  described, 
should  be  noted  for  cross-reference  into  a  subclass  of  Printing  designed  to  receive  the 
inking  mechanism  as  a  part  of  the  printing  press. 

(7)  After  a  knowledge  of  the  material  of  the  class  has  been  obtained 
by  estimating  the  resemblances  between  the  individual  patents  that 


CLASSIFICATION    OF   PATENTS.  39 

have  been  assembled  in  the  several  groups,  comparison  of  these  groups, 
represented  by  the  bundles  of  photolithographs,  by  the  aid  of  the 
approximate  definitions  and  notes  attached  can  be  made.  It  can 
then  be  decided  whether  all  of  these  groups  are  to  be  retained  in  the 
proposed  class,  and  the  retained  groups  can  be  organized  into  a  class 
with  the  subclasses  arranged  so  as  to  bring  those  subclasses  having 
the  strongest  resemblances  in  closest  relation,  and  in  such  order  as  to 
comply  with  the  conventions  adopted  in  the  official  classification. 
It  will  probably  be  necessary  to  have  one  subclass  or  group  as  broad 
as  the  definition  of  the  class,  to  take  unclassifiable  matter  and  to 
provide  for  possible  future  inventions. 

(8)  Up  to  this  point,  more  or  less  cursory  attention  may  be  given 
individual  patents;  but  when  an  arrangement  of  subclasses  shall  have 
been  tentatively  adopted  it  will  be  necessary  to  consider  each  patent 
carefully  to  ascertain  whether  it  is  properly  placed. 

(9)  Patents    that,   considered   as   an   entirety,   cover   means   not 
peculiar  to  the  class  or  subject-matter  being  revised,  should,  in  general, 
when  assembled  in  groups  as  indicated,  have  a  note  attached  indi- 
cating not  only  want  of  limitation  to  the  subject-matter  of  th.3  class 
but  also  a  more  appropriate  class  to  receive  them  if  such  there  be. 
Although  a  very  large  proportion  of  patents  can  be  accurately  classi- 
fied as  indicated  by  their  titles  and  stated  uses,  the  mere  fact  that  in  a 
patent  found  in  a  class  the  invention  is  called  in  the  specification  or 
claims  by  a  name  peculiar  to  the  class  is  not  of  itself  a  reason  for  con- 
sidering it  peculiar  to  the  class.     A  gas  and  liquid  contact  apparatus 
may  be  called  a  heater,  a  cooler,  a  gas-washer,  a  water-carbonator,  a 
condenser,  a  disinfecter,  an  air-moistener,  and  so  on,  depending  upon 
accident  of  use.     If  there  are  not  elements  in  some  claim  to  confine 
the  means  described  distinctively  to  what  it  is  called,  or  if  there  are 
no  functions  necessarily  implied  in  the  means  claimed  peculiar  to  the 
named  use,  the  patent  should  not  be  kept  in  the  class  unless  there  is 
no  other  class  in  the  office  that  can  receive  it. 

Example:  Where  the  matter  claimed  is  a  metal  beam  of  peculiar  cross-section,  it 
should  be  classified  with  other  metal  beams,  as  in  Class  189,  Metallic  Building  Struc- 
tures, even  if  it  is  named  in  the  application  as  a  beam  of  particular  use,  as  a  railroad- 
tie,  car-sill,  bridge-tie,  etc.  Should  a  mere  dash-pot  be  found  classified  in  Class  171. 
Electricity,  Generation,  a  note  should  be  attached  indicating  that  it  belongs  in  the 
appropriate  element  class. 

(10)  In  giving  this  final  careful  attention  to  the  patents,  each 
should  also  be  scanned  to  see  whether  it  contains  matter  that  should 
be  cross-referenced.     A  few  lines  obscurely  located  in  a  specification 
may  contain  a  disclosure  of  a  most  valuable  invention.     No  class 
can  be  deemed  complete  until  the  disclosures  appropriate  to  it  found 
as  parts  of  more  complex  inventions  in  other  classes,  or  disclosures 
of  analogous  matter  in  other  classes,  are  either  cross-referenced  into 
it  or  cross  search-notes  made. 


40  CLASSIFICATION    OF   PATENTS. 

(11)  To  indicate  cross-references,  from  one  subclass    to  another 
within  the  class  or  from  the  class  under  consideration  into  another 
class,  attach  a  small  slip  of  paper  to  the  patent  and  mark  on  the  slip 
the  subclass  number  in  which  the  cross-reference  shall  be  mounted. 
If  the  matter  to  be  cross-referenced  relates  only  to  a  portion  of  a 
voluminous  patent,  the  portion  of  the  specification  and  drawing  to 
be    cross-referenced   should   be   indicated.     If     the    cross-reference 
falls  outside  the  class,  the  class  number  should  be  noted  in  addition 
to  the  subclass  number. 

(12)  Should  it  be  found  that  the  handling  of  copies  in  making 
examinations  detaches  the  cross-reference  slips,  it  may  be  advisable 
to  mark  lightly  but  legibly  in  pencil  on  the  lower  right-hand  corner 
of  the  examiner's  photolithograph  the     number  of  the  subclass  or 
subclasses  into  which  it  is  to  be  cross-referenced,  or  the  number  of 
the  class  and  subclass  in  case  it  is  to  be  cross-referenced  to  another 
class. 

(13)  Whether  cross-reference  notations  are  written  on  a  separate 
slip  or  on  the  photolithograph,  the  number  of  the  class  and  subclass 
into  which  a  patent  is  to  be  cross-referenced  should  always  be  pre- 
ceded  by  X  (thus  X  101-23)  in  order  to  distinguish  the  original 
classification  notation  from  the  cross-reference  notation  and  enable 
sorting  and  indexing  to  be  done  without  confusion. 

(14)  To  indicate  cross-references  from  other  classes  into   the  one 
being  reclassified,  set  down  the  number  of  the  patent  in  a  notebook, 
placing  after  the  number  (1)  the  class  and  subclass  in  which  it  is 
classified;   and  (2)  the  number  of  the  class  and  subclass  in  which  it 
is  to  be  cross-referenced. 

(15)  Should  new  subclasses  be  formed  or  transfers  of  patents  be 
determined  on,  and  lists  of  the  patents,  instead  of  copies  thereof, 
be  furnished  clerks  for  the  purpose  of  making  such  subclasses  and 
transfers  and  correcting  the  official  indexes  and  other  records,  each 
patent  should  be  listed  by  number  in  column  to  the  left  of  a  sheet  of 
paper  or  notebook,  and  opposite  each  patent  number  on  the  same 
sheet  should  be  written  (1)  the  number  of  the  class  and  subclass  in 
which  it  is  officially  classified;  (2)  the  number  of  the  class  and  sub- 
class to  which  it  is  intended  to  transfer  it;   and  (3)  the  numbers  of 
the  classes  and  subclasses,  preceded  by  X,  into  which  it  is  intended 
to  cross-reference  it. 

Note:  Even  though  examiners  engaged  in  reclassifying  are  confident  of  their  ability 
to  classify  and  arrange  on  better  principles  than  those  that  have  been  applied  thus 
far  in  the  classification,  they  ought,  nevertheless,  to  follow  those  principles  under 
which  one-half  of  the  patents  have  been  classified.  Until  the  Commissioner  of 
Patents  orders  examiners  to  classify  on  other  principles,  it  is  expected  they  will 
follow  those  now  established. 

o 


14  DAY  USE 

RETURN  TO  DESK  FROM  WHICH  BORROWED 


LOAN  DEPARTMENT 

This  book  is  due  on  the  last  date  stamped  below,  or 

on  the  date  to  which  renewed. 
Renewed  books  are  subject  to  immediate  recall. 


RPR 


,2    13733* 

EK'DLO    MAR  2 

'73-3PII88- 

LD21-35Tn-8,'72 
(Q 1189810)  476 — A-32 


General  Library 

University  of  California 

Berkeley 


